ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Articles  (105)
  • resistance  (105)
  • Springer  (105)
  • American Chemical Society
  • 1995-1999  (105)
  • Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition  (105)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Integrated pest management reviews 1 (1995), S. 65-69 
    ISSN: 1572-9745
    Keywords: Glycine max ; Heterodera glycines ; inheritance ; resistance ; soybean ; soybean cyst nematode
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Genetics of resistance to soybean cyst nematode (SCN), Heterodera glycines Ichinohe is very complex. Crosses involving PI 437654, which is resistant to all races of cyst nematodes with other sources of resistance (Peking, PI 88788, and PI 90763) indicated that resistance to race 3 was controlled by four genes, two of which were dominant resistance genes and the other two were recessive resistance genes. For race 5, a four gene model with two recessive and two dominant resistance genes in epistasis has been proposed. For race 14, the results suggested a three gene model with one dominant and two recessive alleles. Several other plant introductions have been isolated which have different genes conditioning resistance. Most of the currently grown soybean varieties derived resistance from Peking and/or PI 88788. Resistance to SCN in these soybean varieties has broken down because of the emergence of several new races and populations of SCN. The use of PI 437654 or Hartwig and other plant introductions with different genes for resistance will broaden genetic diversity and stabilize yield.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Integrated pest management reviews 3 (1998), S. 209-224 
    ISSN: 1572-9745
    Keywords: cassava ; Manihot esculenta ; Africa ; cassava mosaic virus disease ; whitefly vector (Bemisia tabaci) ; control ; varietal diversity ; resistance ; deployment ; durability ; breakdown ; phytosanitation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Cassava mosaic virus disease (CMD) is prevalent and causes serious losses in cassava (Manihot esculenta) in southern India and in many parts of sub-Saharan Africa. The disease is caused by viruses of the Geminiviridae that are transmitted by the whitefly Bemisia tabaci and disseminated in the stem cuttings used routinely for propagation. The main approach to control is through the use of virus-resistant varieties, but suitable ones are not always available and susceptible varieties are still widely grown. This explains why CMD continues to be a problem in many areas. CMD-resistant varieties have several features which are considered in this review:- • They are not readily infected, even when exposed to large amounts of vector-borne inoculum. • When infected they develop symptoms that tend to be inconspicuous and not associated with obvious deleterious effects on growth or yield. Moreover, the symptoms become even less conspicuous as growth proceeds and plants may eventually recover and become symptomless. • Infected plants support a low virus content and they are likely to be a poor source of inoculum from which further spread can occur. • Virus is not fully systemic within infected plants which can be a source of uninfected planting material when stem cuttings are collected for further propagation. This phenomenon is referred to as ‘reversion’ and it has an important ‘cleansing effect’ in restricting or preventing the progressive deterioration in health status that would otherwise occur during successive cycles of vegetative propagation. The available information on the different components of resistance is discussed and it is concluded that they are inter-related features of the same basic mechanism that restricts virus entry, replication and movement within the host. It is argued that the effectiveness and durability of virus-resistant varieties are likely to be influenced by the way in which they are deployed. However, this topic has received little attention from researchers and there is continuing uncertainty on the effects of CMD on the yield of resistant varieties and on the role of phytosanitation. This involves the use of virus-free planting material and the removal (roguing) of any additional diseased plants that occur. Some consider that these procedures complement the use of virus-resistant varieties and should be adopted, whereas others argue that they are unnecessary and inappropriate. It is concluded that there is considerable scope for utilizing resistant varieties more widely and more effectively than at present, but in doing so it is important to avoid eroding the genetic diversity that is currently such a marked feature of cassava cultivation in Africa.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Potato research 41 (1998), S. 143-153 
    ISSN: 1871-4528
    Keywords: resistance ; Solanum tuberosum L. cultivars ; glycoalkaloids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The influence of freeze dried potato powder derived from tubers (cvs Désirée and Epicure) exposed to light as a culture medium on the growth, number and spore size of nine fungal pathogens was determined in vitro with particular emphasis on the role of glycoalkaloids. Greater reductions in pathogen growth reflected increased exposure to light of tubers prior to freeze drying. High correlations (% R2 adj) were obtained between glycoalkaloid concentration and growth rate of the majority of pathogens tested. Where spores were produced, numbers were in general significantly less when cultured on freeze dried powder derived from tubers exposed to light. No effects on spore size ofFusarium species were recorded, but spore length of remaining pathogens was reduced and spore width increased, with the exception ofC. coccodes where spore length and width was increased following culture onto freeze dried powder derived from tubers exposed to light.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Potato research 38 (1995), S. 199-210 
    ISSN: 1871-4528
    Keywords: PVY ; resistance ; progeny tests ; inheritance ; potato breeding ; Solanum tuberosum L
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Segregation for extreme resistance to PVY was evaluated in progenies derived from crossing two extremely resistant potato clones with parents differing in resistance. Resistance was evaluated after mechanical inoculation with PVYO and PVYN, and after graft inoculation with PVYO. Biological and serological tests (ELISA) were used for virus detection. The extreme resistance is governed by a single dominant gene, but observed segregations deviated from the expected ratios. Considerable modifying effects were detectable, depending on the potato genotype and virus isolate, for a significant excess of susceptible genotypes was observed in some progenies. Moreover, genotypes with non-parental types of resistance to PVY were observed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1871-4528
    Keywords: bacterial wilt ; resistance ; transformation ; Agrobacterium ; S. tuberosum L. ; transgenic plant
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Transgenic potato plants of cv. Désirée carrying an antibacterial gene, coding for a cecropin lytic peptide analogue, were inoculated with a virulent strain ofPseudomonas solanacearum under controlled conditions. The disease index scored during three repeated infection trials indicated an increased variability in plant response among the transgenic lines which gave either a more susceptible or a more resistant response to the pathogen when compared with untransformed Désirée. Immunity toP. solanacearum was not observed, but it was possible to select a group of transgenic lines that showed resistance levels and disease development curves comparable to the field resistant cv. Cruza 148.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1871-4528
    Keywords: post harvest disease ; potato ; Solanum tuberosum L. ; resistance ; toxin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Virulence of 12Fusarium oxysporum isolates was determined on three potato cultivars Late Harvest, BP1 and Kimberley Choice. The production of fusaric acid by the 12F. oxysporum isolates was also determined. The aim of the study was to determine whether a correlation exists between fusaric acid production and virulence ofF. oxysporum isolates. Late Harvest was the most tolerant and BP1 the most susceptible cultivar. Virulence ranking, order of theF. oxysporum isolates with the different cultivars corresponded with the mean of value of the ranking order for all three cultivars. A correlation was found between virulence of isolates and fusaric acid production except for Late Harvest. Fusaric acid production may play a major role in the development of dry rot in potato tubers.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Potato research 40 (1997), S. 317-326 
    ISSN: 1871-4528
    Keywords: Solanum spp. ; Globodera rostochiensis ; G. pallida ; biology ; pathotypes ; damage ; resistance ; tolerance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary A description of the biology of potato cyst nematodes,Globodera rostochiensis andG. pallida, and symptom development in potato crops is presented. This is followed by an overview of resistance and tolerance research and an explanation of how resistance derived fromSolanum andigena was deployed in integrated control schemes on sandy and sandy peat soils in the north-east of The Netherlands. The frequent use of this resistance source resulted in the predominance of ‘new’ pathotypes ofG. rostochiensis and ofG. pallida. The ability of the cyst nematodes to respond to new types of resistance with new pathotypes makes the search and breeding for resistance a continuing process. The absence of tolerance in exS. vernei (VTn)2 62-33-3 cultivars showed that resistance, if it is to be of use in severely infested fields, must be combined with an appreciable level of tolerance.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1871-4528
    Keywords: antibiosis ; antixenosis ; Solanum sparsipilum ; S. pinnatisectum ; S. berthaultii ; glandular trichomes ; resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Four introductions ofSolanum berthaultii wild species and sevenS. tuberosumxS. berthaultii hybrids were evaluated by antibiosis and antixenosis laboratory tests with potato tuber moth. Some morphological and chemical traits related to the trichomes were analysed. Two clones of the wild speciesS. sparsipilum and five ofS. pinnatisectum, characterised by high tuber resistance, were tested for leaf resistance, both by antibiosis and antixenosis assays. The genotypes with high density of trichomes A and with high exudate PPO activity, showed a moderate negative effect on pupal weight and fecundity in the antibiosis tests. Trichomes B exudate showed a strong repulsive effect on oviposition of adult in the antixenosis tests. TheS. pinnatisectum clones revealed a good leaf resistance level, whereas theS. sparsipilum clones showed lower levels of antibiosis and antixenosis.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Potato research 39 (1996), S. 395-401 
    ISSN: 1871-4528
    Keywords: germplasm ; TPS ; resistance ; rapid multiplication ; virus ; collaborative research ; research priorities
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary After an initial phase of development and programme establishment the activities of the International Potato Center (CIP) grew rapidly from 1981 to 1985, putting emphasis on germplasm distribution, research on diffused-light storage and TPS, and exploration of sources of resistance. Later, strong emphasis was given to genetic resource utilization and field resistance to late blight. The impact of CIP research showed internal rates of return ranging from 26 to 102 percent. At the end of the 1980s CIP's financial resources were cut severely and restructuring the programme was necessary. Through a careful process of prioritizing, programmes are identified which will contribute most to ensuring the continued increase of potato production in developing countries and to continuing the leading role of CIP in potato research.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1572-9788
    Keywords: Helianthus annuus ; QTL ; resistance ; RFLP ; Sclerotinia scerotorum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Restriction fragment length polymorphism and isoenzyme markers were used to investigate quantitative trait loci involved in sunflower resistance to mycelial extension of Sclerotinia sclerotiorum on leaves and capitula. Seed weight, oil content and flowering data were also evaluated. Four quantitative trait loci were demonstrated for leaf resistance and two for capitulum resistance. One of these zones appears involved in resistance to both types of S. sclerotiorum attack while the others appear specific for resistance of one part of the plant. Two quantitative trait loci were detected for seed weight, three for oil content and three for flowering date. Individual quantitative trait loci explained 9% to 48% of the phenotypic variability, confirming the polygenic basis of the quantitative traits studied. Overall, the quantitative trait loci explain 60% of the genetic variation for leaf resistance and 38% for capitulum resistance to S. sclerotiorum. One linkage group is particularly interesting since it includes quantitative trait loci for all the five quantitative traits measured. Hypotheses for linkage versus pleiotropy and consequences of all the results in resistance breeding are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Molecular breeding 3 (1997), S. 213-217 
    ISSN: 1572-9788
    Keywords: geminiviruses ; beet curly top virus ; DI DNA ; resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Beet curly top virus (BCTV) infection is associated with the de novo synthesis of a heterogeneous population of subgenomic viral DNAs. Nicotiana benthamiana plants transformed with a partial repeat of one such subgenomic DNA remained susceptible to infection but produced ameliorated symptoms when agroinoculated with BCTV. Symptom amelioration is associated with the mobilization of subgenomic DNA from the integrated copy. In an attempt to improve the resistance, N. benthamiana has been transformed with a partial repeat of a much smaller subgenomic DNA. However, transgenic plants showed almost no resistance although subgenomic DNA was mobilised from the host genome. To further understand the molecular basis of the interference phenomenon, we compared the ability of BCTV to replicate and accumulate in leaf discs derived from resistant and non-resistant transgenic plants. Both subgenomic DNAs were able to interfere with virus replication but only in case of resistant plants the DI DNA efficiently suppressed viral accumulation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    Electronic Resource
    Electronic Resource
    Springer
    European journal of plant pathology 102 (1996), S. 773-778 
    ISSN: 1573-8469
    Keywords: apple scab ; environmental factors ; resistance ; Venturia inaequalis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The susceptibility of apple leaves toVenturia inaequalis was investigated by assessing disease on individual leaves of seedlings and labelled shoots of orchard trees. Four sets (A-D) of potted seedlings of cv. ‘Golden Delicious’, which had been grown in a glasshouse, each with approximately 30 mature leaves, were exposed to a high-inoculum orchard. Sets A and B were exposed after each other for 47 and 42 days, respectively. As a result of the six and three infection periods during exposure, 94% and 81%, respectively of the seedling shoot tips in set A and set B became infected. However, due to ontogenetic resistance, disease incidence was low in both sets on leaves which were fully expanded at the beginning of exposure. Set C was exposed during both periods (89 days) in which sets A and B were exposed. Not only were all the seedling shoot tips in set C infected, but also — due to the loss of ontogenetic resistance — nearly all of the mature leaves. Ontogenetic resistance was also lost in set D, which was exposed for 57 days at the end of the growing season. The symptoms on fully expanded leaves on plants in sets C and D were typical and similar to those on young leaves. A time course symptom assessment was performed on leaves which had developed early in the season on labelled, field-grown shoots of cv. ‘Golden Delicious’ trees. A steady increase of disease incidence was detected, which could not only have resulted from infections followed by extended incubation periods. In addition to the increase of typical lesions on both leaf surfaces, there was also an abundance of diffuse mycelial development on the lower surfaces of the leaves of the field-grown trees.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    Electronic Resource
    Electronic Resource
    Springer
    European journal of plant pathology 103 (1997), S. 653-665 
    ISSN: 1573-8469
    Keywords: avoidance ; Melampsora pinitorqua ; path coefficient analysis ; Pinus pinaster ; resistance ; rust
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Data collected in a three-year field experiment on infection and damage by Melampsora pinitorqua on maritime pines showing contrasting growth were analysed by means of path analysis. The severity of infection in 2 year-old pines could be mainly explained by the amount of susceptible tissues (elongating shoots). In contrast, two years later, ‘intrinsic susceptibility’, i.e. expressed after inoculation, was shown to have the most important direct effect on the amount of infection. Intrinsic susceptibility could be satisfactorily assessed by artificial inoculations on excised shoots under controlled conditions. Shoot potassium and phosphorous contents were shown to have marked positive effects on susceptibility. The hypothesis of an age effect on the relative importance of different resistance mechanisms, i.e. avoidance and active resistance, in maritime pine interaction with twisting rust is discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    Electronic Resource
    Electronic Resource
    Springer
    European journal of plant pathology 104 (1998), S. 11-15 
    ISSN: 1573-8469
    Keywords: black pod ; resistance ; Theobroma cacao
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Two species of Phytophthora (P. palmivora and P. capsici) and inoculations at two depths (3 mm and 9 mm) were tested each on 10 clones of Theobroma cacao to determine their effects on pod resistance. Ripe and unripe pods were also assessed to determine the influence of physiological status of the pod on the expression of resistance. The two pathogens tested (P. palmivora and P. capsici) differed significantly in their reactions on pods, with P. palmivora being more aggressive than P. capsici. However, the lack of interaction between clones and pathogen species and the similarity in the ranking of clones based on lesion size suggested that selection for resistant clones can be based on one of the two pathogens, preferably the more aggressive one. Pod reactions differed between inoculation depths (3 mm and 9 mm), and between pod maturity stages (ripe and unripe pods) with relatively larger lesions being recorded at 9 mm depth and on unripe pods as compared to those observed at 3 mm depth and on unripe pods, respectively. The magnitude of increase in lesion sizes, however, varied with genotypes, indicating that inoculation depth and pod maturity stage should be standardized in screening cacao germplasm for resistance to Phytophthora.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    Electronic Resource
    Electronic Resource
    Springer
    European journal of plant pathology 104 (1998), S. 449-455 
    ISSN: 1573-8469
    Keywords: lettuce ; lettuce downy mildew ; Bremia lactucae ; phenylamide fungicides ; virulence factors ; resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Control of lettuce downy mildew (Bremia lactucae) with phenylamide fungicides has failed in some intensive lettuce-producing areas in Northern Italy since Spring 1993. Before then, these chemicals and particularly metalaxyl, provided the best disease control. The sensitivity of Bremia lactucae isolates collected in such areas to metalaxyl was evaluated in the laboratory. These strains grew and sporulated profusely on lettuce seedlings treated with 100 and 200 ppm of metalaxyl, whereas sensitive control strains were completely inhibited when treated with fungicide concentrations ranging from 0.5–1 ppm. Thus in Italy occurrence of resistance to phenylamide fungicides in Bremia lactucae has also been demonstrated, as in almost all the countries where these chemicals were previously authorised. Subsequently, a demonstration of occurrence of resistance was made and the virulence pattern of several strains (resistant and sensitive to metalaxyl) was characterised using differential NL series containing the 13 DM resistant genes or R factors. The results suggest the occurrence of a new pathotype in Italy different from all the 16 NL Bremia lactucae races studied.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    Electronic Resource
    Electronic Resource
    Springer
    European journal of plant pathology 105 (1999), S. 431-443 
    ISSN: 1573-8469
    Keywords: basal rot ; cell wall degradation ; Lilium ; pathogenesis ; plasmolysis ; resistance ; transfer cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The early interaction of lily roots with the cortical rot pathogen Fusarium oxysporum f.sp. lilii was studied using roots of lily bulblets grown in Hoagland's solution, inoculated with the pathogen, and sampled up to 48 h later. Conidia produced germ tubes within 6 h, which extended towards and into the mucilage covering the root elongation zone, and along and into the anticlinal grooves and middle lamellae of epidermal cells. By 24–48 h, infecting hyphae had reached the periclinal walls and intercellular spaces between the epidermis and the outermost cells of the cortex. Penetration of intercellularly growing hyphae directly across host cell walls was not observed; invasion of the cell lumen only occurred by gradual infringing of hyphae upon successive primary wall layers. Non-cellulosic wall appositions rich in vesicles and covered by a cellulosic protective-like layer were formed in response to approaching hyphae in resistant cv.Connecticut King, but rarely in susceptible cv. Esther which seemed more susceptible to plasmolysis and rot. Finger-like projections of the appositions into the host cell cytoplasm likely represent early stages of transfer cell formation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    ISSN: 1573-8469
    Keywords: Ceratocystis fimbriata ; phytoalexins ; Platanus spp. ; resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Inoculation of leaves of resistantPlatanus occidentalis and susceptiblePlatanus acerifolia leaves withCeratocystis fimbriata f. sp.platani, the canker stain disease agent, induced foliar necrosis and biosynthesis of two phytoalexins, scopoletin and umbelliferone. Foliar symptoms keep localized and accumulation of coumarin phytoalexins was rapid for incompatible interactions. Necrosis spread widely and accumulation of these phenolic compounds was much later and lower for compatible interactions. The differential response could be used in a genetic improvement program for resistance against canker stain.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    Electronic Resource
    Electronic Resource
    Springer
    European journal of plant pathology 102 (1996), S. 311-316 
    ISSN: 1573-8469
    Keywords: Capsicum annuum ; C. frutescens ; resistance ; Phytaphthora capsici ; host-pathogen interaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Pepper cultivars from diverse geographic origins were evaluated for resistance to different isolates ofPhytophthora capsici under controlled environmental conditions. All accessions tested were susceptible at the four-leaf stage to the six isolates ofP. capsici. Inoculation at the eight-leaf stage resulted in significantly different interactions among the accessions andP. capsici isolates. The Korean and U.S. cultivars tested were highly susceptible to the isolates ofP. capsici at this stage. In contrast, PI 201234 and PI 201238 had a differential interaction with someP. capsici isolates. At the twelve-leaf stage, Phytophthora blight developed slowly in the Korean and U.S. cultivars that were highly susceptible at the eight-leaf stage. Furthermore, the accessions from the Asian Vegetable Research and Development Center (AVRDC) became highly resistant toP. capsici at this stage.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    Electronic Resource
    Electronic Resource
    Springer
    European journal of plant pathology 103 (1997), S. 15-23 
    ISSN: 1573-8469
    Keywords: breeding ; Dianthus caryophullus ; Fusarium oxysporum ; pectic enzymes ; phytoalexins ; resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Carnation cultivars with different levels of partial resistance were inoculated with race 2 of Fusarium oxysporum f.sp. dianthi and monitored for accumulation of host phytoalexins, fungal escape from compartmentalization, production of fungal pectin-degrading enzymes and development of external disease symptoms. Accumulation of phytoalexins, assessed after 10 days in the first 5 cm above the inoculation site, was weakly (methoxydianthramide S) or not (hydroxydianthalexin B) correlated with resistance levels after 12 weeks. Fungal escape from compartmentalization, assessed after 3 weeks as percentages colonized plants at 8 cm above the inoculation site, was highly correlated with expression of susceptibility after 12 weeks. Polygalacturonase (PG) activity, assessed after 4 weeks in the first 5 cm above the inoculation site, was highly correlated to final disease development. Linear increases in disease severity were accompanied by quadratic increases in PG activity. In contrast to water-treated plants, that lacked any PG activity, inoculated plants contained two main groups of fungal PGs, the dominant forms of which had estimated pI values of 7.0 and minimally 9.5, respectively. Compared to those of the first group, enzymes of the second group were produced only in trace amounts in liquid media containing pectin or polygalacturonate as sole source of carbon. On these media, the fungus also produced a pectin methyl esterase (PME) with an estimated pI of 9.3. Besides PMEs of host origin, inoculated plants of susceptible cultivars contained the fungal PME while no more than traces were found in resistant ones. Assessment of phytoalexin production by the host during defense responses cannot replace monitoring of external symptoms as a resistance test. Assessment of fungal growth, whether by reisolations above the compartmentalization area or by measurement of PG activity, provides a both rapid and reliable prediction of disease development.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    Electronic Resource
    Electronic Resource
    Springer
    European journal of plant pathology 105 (1999), S. 509-512 
    ISSN: 1573-8469
    Keywords: tospovirus ; resistance ; Capsicum sp. ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Infection by two isolates of impatiens necrotic spot tospovirus (INSV) under temperature regimes of 25/18°C (day/night) or 33°C (continuous) was studied in Capsicum annuum (systemically susceptible to tomato spotted wilt tospovirus, TSWV), C. chinense PI 152225 and PI 159236 (reacting hypersensitively to TSWV) and Nicotiana benthamiana (systemically susceptible to both tospoviruses). At 25/18°C infection was systemic in all hosts tested. At 33°C infection in N. benthamiana was systemic whereas in C. annuum and C. chinense it was restricted to the inoculated leaves. The result differed from that reported for TSWV, where high temperature made plants more susceptible, or caused no difference. Exchanging temperature regimes 6 h to 4 days after inoculation did not affect the final results one month later, with plants being only locally infected at 33°C continuous regime, or systemically infected at 25/18°C alternate regime. The two INSV isolates were biologically and serologically stable for 5 passages in N. benthamiana held continuously at 33°C.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 21
    ISSN: 1573-8469
    Keywords: Phytophthora infestans ; potato ; wild Solanum spp. ; resistance ; detached leaves
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Physiological and molecular research on resistance responses of Solanum tuberosum cultivars and partially resistant Solanum species to Phytophthora infestans requires a reliable resistance test that can be used in the laboratory. Laboratory tests performed on detached leaves and intact plants were compared with field tests for similarity of late blight reactions. Detached leaves from field-grown plants were as resistant as detached leaves from climate chamber-grown plants when challenged with P. infestans. However, detached leaves incubated in covered trays at high relative humidity were more susceptible than detached leaves kept in open trays or leaves on intact plants. The incubation conditions of detached leaves in covered trays rather than detachment itself appeared to affect the resistance expression. Detached leaves of some wild Solanum genotypes became partially infected, whereas intact plants were completely resistant when inoculated. Inoculation of leaves on intact plants, however, resulted in lower infection efficiencies. These limitations should be taken into account when choosing the appropriate inoculation method for specific purposes. For resistance screening, laboratory tests proved to be a good alternative for field tests. The ranking of resistance levels for twenty plant genotypes was similar under laboratory and field conditions.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 22
    Electronic Resource
    Electronic Resource
    Springer
    European journal of plant pathology 101 (1995), S. 51-56 
    ISSN: 1573-8469
    Keywords: resistance ; potato breeding ; roots canister test
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Fourteen cultivars generally regarded as uniformly susceptible toGlobodera pallida Pa 2/3 were assessed in plastic closed containers for degree of susceptibility and also for root and sprouting characteristics. The material was assessed by scoring degree of sprouting before planting and number of cysts and root growth at the end of experiment at intervals from the time of initial dormancy break through to prolific sprouting. Using covariate analyses, it was found that the degree of root development, particularly in the earlier assessments, significantly influenced the degree of cyst development and so the perceived levels of susceptibility/resistance. Having taken account of root growth characters, significant differences between the cultivars with regard to nematode multiplication were still evident. The implications of the results are discussed in relation to potato breeding and nematological studies.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 23
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 100 (1998), S. 45-50 
    ISSN: 1573-5060
    Keywords: incidence ; Karnal bunt ; occurrence ; resistance ; variability ; wild relatives ; progenitors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Bunts [common bunt (Tilletia laevis and T. tritici) and dwarf bunt (T. controversa)] and smuts [loose smut (Ustilago tritici) and flag smut (Urocystis agropyri)] of wheat are important cereal diseases in most countries of north Africa and the Near East. There are no peculiarities in the occurrence of bunts and smuts, except for dwarf bunt, which is limited to high-altitude areas of Turkey, Iran and Iraq. Host adaptation, rather than topography, determines the distribution of the common bunt pathogens: T. laevis predominates in bread wheat, whereas T. tritici attacks both bread and durum wheat non-preferentially. Incidence of bunt- and smut-affected wheat heads is generally low, however the frequency of their occurrence in fields is high, indicating their potential threat. Some bunts and smuts occur on hosts other than wheat, for example, flag smut on Aegilops crassa, loose smut on Ae. geniculata and rye, and dwarf bunt on Hordeum and Aegilops spp. Genetic variability of the pathogens causing common bunt and loose smut was investigated. Chemical seed treatment is the most widely used control for bunts and smuts. Organic nutrients as seed treatments to control common bunt of wheat show considerable promise. Sources of resistance to loose smut, and common and dwarf bunts of wheat, are available in wheat and its wild relatives. Triticum boeoticum, T. dicoccoides, and Aegilops species represent excellent sources of resistance to common bunt. There are three major sources of resistance in durum wheats, Senatore Cappelli and Haurani, Jenneh Khetifa, and Mindum. Common bunt resistance genes Bt5, Bt6, Bt8, Bt9, Bt10, and Bt11, and several undescribed resistances remain effective in the screening field at ICARDA, Syria.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 24
    ISSN: 1573-5060
    Keywords: Phytophthora clandestina ; resistance ; root rot disease ; subterranean clover ; Trifolium subterraneum ; virulence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Infection and sporulation of races of Phytophthora clandestina in susceptible and resistant cultivars of subterranean clover and the effect of the races on growth of the cultivars in pots were studied using a total of five races of the pathogen and eight host cultivars. The pathogen caused severe disease where races and cultivars were compatible, although a significant reduction in root and shoot dry weight occurred only on Woogenellup inoculated with race 2. There was little increase in disease severity after 1 wk from the time of inoculation. Sporangia and oospores were formed at high frequency in tap and lateral roots in all compatible combinations, except in Woogenellup in which sporangia were produced inconsistently. The pathogen caused negligible disease and produced very few sporangia in incompatible combinations. Plant age had a strong effect on disease development. Disease severity caused by virulent races on cultivars Gosse, Trikkala, Meteora and Woogenellup was less on older than on younger plants. A further experiment using aggressive isolates of races 0, 1, 2, 3 and 4 revealed that cultivar Gosse showed no reduction in root and shoot weight, despite it being susceptible to races 1, 3 and 4. This provided evidence of the existence of race-non-specific or horizontal resistance to P. clandestina in cultivar Gosse.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 25
    ISSN: 1573-5060
    Keywords: Anthurium ; Radopholus similis ; resistance ; tolerance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Five Anthurium species closely related to two of the cultivated ornamentals, A. andraeanum Lind. ex André and A. scherzerianum Schott, and one species of breeding interest, were screened in vitro for tolerance and resistance to the nematode Radopholus similis Cobb, 1893. Adjustment of the tolerance measurement to the initial and uninoculated treatment measurement improved the screening method. Use of a nematode strain with a relatively slow reproduction rate enabled concurrent screening for tolerance and resistance to R. similis in Anthurium. Based on a lower relative symptom index, A. pittieri Engl., A. ravenii Croat and Baker, A. antioquiense Engl. and A. aripoense N. E. Br. reduce nematode damage as compared to the reference standard, ‘Midori’. However, A. antioquiense and A. aripoense had higher root damage than ‘Midori’. Lower nematode damage in A. pittieri and A. ravenii is positively correlated with greater plant vigor or to fewer target roots for nematode infection. A. ravenii was among the most resistant species as measured by nematode reproduction. This is followed by A. aripoense and A. pittieri. Thus, strong plant vigor, fewer target roots for nematode infection, and/or lower nematode reproduction (higher nematode resistance) resulted in lower nematode damage in A. pittieri and A. ravenii. Combining the nematode damage and nematode reproduction results, A. pittieri and A. ravenii were identified as more tolerant than the reference standard ‘Midori’.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 26
    ISSN: 1573-5060
    Keywords: BSA ; Liriomyza trifolii ; Lycopersicon ; molecular markers ; resistance ; leaf miner
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Resistance to many arthropods, including Liriomyza species, is known to be present in accessions of Lycopersicon hirsutum (f. typicum or f. glabratum). From the cross L. esculentum cv. Moneymaker and L. hirsutum f. glabratum G1561 100 F2 plants were screened in a no-choice test for resistance to Liriomyza trifolii. The Bulked Segregant Analysis approach was used to find Random Amplified Polymorphic DNA markers linked to resistance. Two markers were located on chromosome 2. Restriction Fragment Length Polymorphisms constructed a more detailed genetic linkage map for part of chromosome 2. Kruskal-Wallis analysis showed that this chromosome harbored a Quantitative Trait Locus (QTL) for number of pupae, number of mines and damage. At least one major QTL is essential for resistance and this QTL is located on chromosome 2 nearby the location of the tomato probe TG451.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 27
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 88 (1996), S. 165-174 
    ISSN: 1573-5060
    Keywords: wheat ; tritordeum ; Hordeum chilense ; Fusarium culmorum ; Septoria nodorum ; scab ; deoxynivalenol ; ergosterol ; resistance ; Triticum spp
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Hordeum chilense is a wild barley extensively used in wide crosses in the Triticeae. It could be a valuable source of resistance to Fusarium culmorum and Septoria nodorum. Some H. chilense x Triticum spp. amphiploids, named tritordeums, were more resistant than the parental wheat line to these diseases, others were not. Average contents of ergosterol and deoxynivalenol (DON) suggested that resistance to colonization by Fusarium was the highest for Hordeum chilense, followed by tritordeum and wheat in decreasing order. In particular, the H. chilense genotypes H7 and H17 enhanced the wheat resistance to F. culmorum in its tritordeum offsprings. Resistance to S. nodorum in tritordeum was not associated with tall plant height. There is sufficient genetic variation for resistance to F. culmorum and S. nodorum among tritordeum to allow the breeding of lines combining short straw and resistance to both diseases.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 28
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 96 (1997), S. 273-279 
    ISSN: 1573-5060
    Keywords: Cicer arietinum ; chickpea ; Fusarium oxysporum f.sp. ciceri ; wilt ; screening ; resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A total of 1915 Kabuli chickpea lines were screened in a wilt sick plot containing Fusarium oxysporum f.sp. ciceri race 0 at Béja, Tunisia. Complete resistance was found in 110 lines and this result was confirmed by a laboratory screening method. Principal components analysis showed that 〉 80% of the variation of the resistant lines was explained by hundred seed weight and days to maturity. Cluster analysis divided the resistant lines into four groups: 21 had high seed weight (48.25 ± 3.81 g) and early maturity (95.09 ± 2.50 d), 24 had high seed weight (46.84 ± 2.10 g) and late maturity (117.00 d), 34 had low seed weight (22.35 ± 4.72 g) and early maturity (92.97 ± 3.97 d) and 31 had low seed weight (19.62 ± 5.37 g) and late maturity (112.09 ± 4.51 d).
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 29
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 97 (1997), S. 39-44 
    ISSN: 1573-5060
    Keywords: Agropyron ; Elymus ; Fusarium head blight ; scab ; resistance ; genetic resources ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Four species of indigenous Japanese Agropyron, namely, Elymus humidus Osada (= Agropyron humidum), E. tsukushiensis Honda var. transiens (= A. tsukushiense), E. racemifer Tsvel. (= A. ciliare) and A. mayebaranum var. intermedium Hatusima were collected and evaluated for their resistance to Fusarium head blight (FHB, scab) after inoculation with a conidial suspension of Fusarium graminearum Schwabe at the flowering stage. The resistance to penetration of FHB and to fungal invasion of rachis internodes was evaluated in each accession in a comparison with six wheat cultivars. The results demonstrated that AG.91-35 of E. humidus and AG.91-24 of E. racemifer had higher resistance to penetration than the resistant wheat cultivars Nobeokabouzu-komugi and Sumai 3, respectively. All accessions of indigenous Japanese species of Agropyron examined, with the exception A. mayebaranum, had a statisticallysimilar resistance to invasion, which was the same as that of Nobeokabouzu-komugi or Sumai 3. In all accessions of E. humidus, with only one exception, no spread of the fungus from the infected spikelets to the rachis internodes was detected at all. The possible application of the strains of Agropyron as genetic resources for development of resistance to FHB in wheat is discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 30
    ISSN: 1573-5060
    Keywords: Cajanus Cajan ; inheritance ; isolates ; pigeonpea ; resistance ; sterility mosaic ; susceptibility
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Studies were conducted to determine the inheritance of resistance to two isolates of the sterility mosaic pathogen, in three crosses of pigeonpea, involving resistant (ICP 7035, ICP 7349 and ICP 8850) and susceptible (ICP 8863) lines. Observations of F1 and F2 plants were explained on the basis of two independent non-allelic recessive genes for the less virulent, old Patancheru isolate (isolate 1). The backcrosses corroborated the segregation pattern observed in the F2 generation. For the more virulent, new Patancheru isolate (isolate 2), differential behavior of the F1’s was observed. Resistance was dominant in two crosses (ICP 7035 X ICP 8863 and ICP 7349 X ICP 8863), and susceptibility in the other cross (ICP 8850 X ICP 8863). The disease reaction for isolate 2, appeared to be governed by a single gene with three alleles, with one resistance allele exhibiting dominance and the other being recessive, over the allele for susceptibility. Monogenic inheritance of resistance to both isolates was noticed in the cross ICP 8850 X ICP 8863.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 31
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat-alien translocation ; resistance ; C-banding ; in situ hybridization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Wild relatives of common wheat, Triticum aestivum, and related species are an important source of disease and pest resistance and several useful traits have been transferred from these species to wheat. C-banding and in situ hybridization analyses are powerful cytological techniques allowing the detection of alien chromatin in wheat. C-banding permits identification of the wheat and alien chromosomes involved in wheat-alien translocations, whereas genomic in situ hybridization analysis allows determination of their size and breakpoint positions. The present review summarizes the available data on wheat-alien transfers conferring resistance to diseases and pests. Ten of the 57 spontaneous and induced wheat-alien translocations were identified as whole arm translocations with the breakpoints within the centromeric regions. The majority of transfers (45) were identified as terminal translocations with distal alien segments translocated to wheat chromosome arms. Only two intercalary wheat-alien transloctions were identified, one induced by radiation treatment with a small segment of rye chromosome 6RL (H25) inserted into the long arm of wheat chromosome 4A, and the other probably induced by homoeologous recombination with a segment derived from the long arm of a group 7 Agropyron elongatum chromosome with Lr19 inserted into the long arm of 7D. The presented information should be useful for further directed chromosome engineering aimed at producing superior germplasm.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 32
    ISSN: 1573-5060
    Keywords: biotype ; control method ; cowpea ; inheritance ; resistance ; Striga gesnerioides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Pot and laboratory experiments were performed in order to elucidate the genetics of resistance of three cowpea (Vigna unguiculata (L.) Walp.) resistant sources to two biotypes of the parasitic weed Striga gesnerioides (Willd.) Vatke (witchweed). B301, Suvita-2 and IT82D-849 were crossed to susceptible cultivars. Roots of each plant of parental, F1, F2, BC1 and BC2 populations were washed free of soil and examined closely for S. gesnerioides attachment. Data on resistant and susceptible cowpea plants were analyzed using the chi-square test to ascertain the goodness of fit to different genetic ratios. Segregation patterns indicate monogenic dominant inheritance of resistance to both S. gesnerioides biotypes in B301. Suvita-2, which is susceptible to the biotype from Maradi, Niger, showed segregation patterns that indicate monogenic dominant inheritance of resistance to S. gesnerioides biotype from Cinzana, Mali. Results also indicate monogenic dominant inheritance of resistance to S. gesnerioides biotype from Cinzana in IT82D-849. However, the inheritance of resistance to the biotype from Maradi would be monogenic and recessive in this line. These results suggest that the resistance of all three sources would be easy to transfer to promising breeding lines.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 33
    ISSN: 1573-5060
    Keywords: cowpea severe mosaic virus ; genetics ; selection ; screening ; resistance ; tolerance ; Vigna unguiculata
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract P1, P2, F1, F2, BC1 and BC2 generations of four resistant × susceptible crosses and three resistant × resistant crosses of cowpea (Vigna unguiculata L. Walp) were screened for resistance to cowpea severe mosaic virus (CPSMV), in an insect protected screen house. The segregation ratio, at maturity, showed a 63 susceptible : 1 resistant ratio in the F2 generation indicating that resistance is governed by three major genes. The backcross tests and the F3 test confirmed this. The intermediate levels of symptoms observed in the F1 generation and the progression of symptom expression in the F2 generation suggested that resistance is gene dosage dependent. The genetic basis of immunity, tolerance, high level of resistance is discussed based on the three gene model. Delayed symptom expression was evident in genotypes with one or two susceptible alleles. The implications of delayed expression of symptoms in selection and breeding for resistance to CPSMV are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 34
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 192 (1997), S. 23-30 
    ISSN: 1573-5036
    Keywords: aluminium ; callose ; protoplasts ; resistance ; toxicity ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The screening of 37 Zea mays L. cultivars in nutrient solution using root elongation (24 h) as a parameter showed large genotypic differences in Al resistance among the genetic material evaluated. Callose concentrations in root tips were closely and positively related to Al-induced inhibition of root elongation. Therefore, Al-induced callose formation in root tips appears to be an excellent indicator of Al injury and can be used as a selection criteria for Al sensitivity. In contrast, aluminium concentrations in root tips were not related to Al-induced inhibition of root elongation, nor to Al-induced callose formation. Callose formation was also induced by short-term A1 treatment in root tip protoplasts, and the response of protoplasts clearly reflected the cultivar-specific response to Al of intact roots. This indicates that in maize, Al sensitivity is expressed on the protoplast level.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 35
    ISSN: 1573-5036
    Keywords: aluminium ; binding forms ; element compartmentation ; Picea abies ; resistance ; root exudates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In order to investigate if Al resistance in Norway spruce (Picea abies[L.] Karst.) can be attributed to similar exclusion mechanisms as they occur in several crop plants, three-year-old Norway spruce plants were treated for one week in hydroculture with either 500 μM AlCl3 or CaCl2 solutions at pH 4. Sequential root extraction with 1 M NH4Cl and 0.01 M HCl and EDX microanalysis revealed that Al and Ca in cell walls and on the surface participated in exchange processes. About half of the Al extracted by the sequential extraction was not exchangeable by 1 M NH4Cl. Phenolics and phosphate present in the root extracts are possible ligands for Al adsorbed to or precipitated at the root in a non-exchangeable form. In both treatments, C release during the first period of 2 d was much higher than during the remaining time of the experiment. Al treated plants released less total C, carbohydrates and phenolics than did Ca treated plants. Acetate was the only organic acid anion that could be detected in some samples of both treatments. Free amino acids were present at micromolar concentrations but as hydrolysis did not increase their yield, there was no evidence of peptide release. One to two thirds of the released C were large enough not to pass a 1 kDa ultrafilter. The results suggest that exudation of soluble organic complexors is not a major Al tolerance mechanism in Norway spruce, although complexation of Al by phenolic substances released by the root could be detected by fluorescence spectroscopy. Aluminium tolerance could rather be attributed to immobilization in the root apoplast, where strong binding sites are available or precipitation may occur.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 36
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat ; Puccinia recondita ; leaf rust ; breeding ; resistance ; yield ; yield components
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The most important breeding objectives in crop improvement are improving grain yield, grain quality, and resistances to various biotic and abiotic stresses. The objectives of our study were to compare two crossing and four selection schemes for grain yield, yield traits, and slow rusting resistance to leaf rust (Puccinia recondita) based on additive genes in wheat (Triticum aestivum), and to identify the most efficient crossing and selection methodologies in terms of genetic gains and cost efficiency. Segregating populations were derived from 18 simple crosses and the same number of top (three-way) crosses. Half of the crosses were derived from Yecora 70 and the other half from Veery #10 as the common leaf rust susceptible parents. The four selection schemes were: pedigree, modified bulk (F2 and F1-top as pedigree, selected lines in F3, F4, F2-top, F3-top as bulk; and pedigree in F5 and F4-top populations), selected bulk (selected plants in F2, F3, F4, F1-top, F2-top and F3-top as bulk; and pedigree in F5 and F4-top populations), and nonselected bulk (bulk in F2, F3, F4, F1-top, F2-top and F3-top; and pedigree in F5 and F4-top populations). A total of 320 progeny lines, parents and checks were tested for grain yield, other agronomic traits and leaf rust resistance during the 1992/93 and 1993/94 seasons in Ciudad Obregon (Sonora State, Mexico) which represents a typical high yielding irrigated site. The influence of the type of cross and the selection scheme on the mean grain yield and other traits of the progenies was minimal. The selection of parents was the most important feature in imparting yield potential and other favourable agronomic traits. Moreover, the highest yielding lines were distributed equally. Progeny lines derived from Veery #10 crosses had significantly higher mean grain yield compared to those derived from the Yecora 70 crosses. Furthermore, a large proportion of the highest yielding lines also originated from Veery #10 crosses. Mean leaf rust severity of the top cross progenies was lower than that of the simple cross progenies possibly because two parents contributed resistance to top cross progenies. Mean leaf rust severity of the nonselected bulk derivatives was twice that of lines derived from the other three schemes. Selected bulk appears to be the most attractive selection scheme in terms of genetic gains and cost efficiency.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 37
    ISSN: 1573-5060
    Keywords: diallel analysis ; Fusarium culmorum ; heterosis ; resistance ; scab ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Fusarium head blight (FHB, scab) caused by Fusarium spp. is a widespread disease of cereals causing relevant yield and quality losses and contaminating cereal products with mycotoxins. Breeding resistant cultivars is the method of choice for controlling the disease. Resistance to FHB is a quantitative trait and is most likely governed by several genes. We present the results of an F1 diallel analysis of FHB resistance involving six resistant and one susceptible European winter wheat genotypes of diverse origin in order to identify promising combinations for the selection of improved cultivars. Parents and F1s including reciprocals were evaluated for FHB resistance in an artificially inoculated field trial. Two traits were assessed: visual disease symptoms on the heads and the percentage of Fusarium damaged kernels in a harvested sample. General combining ability (GCA) and specific combining ability (SCA) effects were statistically significant for visual symptoms and kernel damage, whereas reciprocal effects were small or not significant. Heterosis for resistance was common, indicating that the parental genotypes possess different resistance genes. Selection of transgressive segregates should be feasible from such heterotic combinations.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 38
    ISSN: 1573-5060
    Keywords: Collapse ; cucumis melo ; melon ; resistance ; sudden wilt ; variation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Differences in the response of melon genotypes to the sudden wilt disease were observed in several field trials conducted during 1993–1994 in the Arava region of southern Israel. Generally, the disease was more severe in the late summer growing season which is shorter and has higher temperatures than the spring and autumn growing seasons. The Oriental pickling melon breeding line P6a was the most tolerant among the entries tested. The response to the disease was also studied using two segregating families and their progenitors. BSK (tolerant) × P202 (susceptible) and P6a (tolerant) × D17 (susceptible). Wilting percentages of F1, F2 and backcross families were intermediate between the parents, suggesting an additive mode of gene action.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 39
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 96 (1997), S. 327-330 
    ISSN: 1573-5060
    Keywords: amphiploids ; Karnal bunt ; resistance ; Tilletia indica ; tritordeum ; Hordeum chilense
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Reactions of Hordeum chilense accessions H1 and H7 and their amphiploids, HT8, HT9 and HT28 (named as tritordeum) alongwith wheat lines, T22, T24 and T59 used in their synthesis, were studied for resistance to the Karnal bunt pathogen (Tilletia indica) of wheat. Both the accessions of H. chilense and one tritordeum line, HT8, were rated as highly resistant with zero co-efficient of infection, whereas the other two tritordeum lines HT28 and HT9 were rated as moderately susceptible and susceptible with 5.2 and 10.5 co-efficients of infection, respectively, compared to reaction of the wheat lines involved in their synthesis. Karnal bunt infection was maximum on the susceptible wheat cultivar WL-711 with 24.3 co-efficient of infection. All the wheat lines involved in the synthesis of amphiploids were susceptible to Karnal bunt except, T59 (Triticum sphaerococcum) (6X), which showed a moderate level of resistance.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 40
    ISSN: 1573-5060
    Keywords: head scab ; resistance ; Triticeae ; Fusarium graminearum ; ecological conditions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract 1507 accessions from 93 species of 18 genera in Triticeae were screened for resistance to initial infection and resistance to pathogen spread with multi-floret and single-floret injection inoculation methods respectively. The accessions with high resistance were mainly found in perennial genera: Roegneria, Hystrix, Agropyron, Kengyilia and Elymus. Based on differences in resistance, 18 genera screened in Triticeae could be classified into five groups. The species with high resistance were mainly distributed in humid ecological environments.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 41
    ISSN: 1573-5060
    Keywords: Phytophthora clandestina ; resistance ; root rot disease ; subterranean clover ; Trifolium subterraneum ; virulence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The resistance of 19 cultivars of subterranean clover was screened against 4 races of P. clandestina by mycelial inoculation of roots of 10-day-old seedlings growing in water agar and by growing seedlings in pasteurised potting mix containing infested vermiculite in controlled conditions. The cultivars showed differential resistance (vertical resistance) to races of the pathogen and can be divided into 4 resistance groups. Cultivars Clare, Esperance, Green Range, Junee, Mount Barker, Rosedale, Woogenellup and Yarloop were susceptible to all races. Cultivars Bacchus Marsh, Denmark, Enfield, Gosse, Goulburn, Karridale, Larisa, Leura and Trikkala were susceptible to races 1 and 3, but resistant to races 0 and 2. Cultivar Meteora was susceptible to races 2 and 3, but resistant to races 0 and 1. Cultivar Seaton Park (LF) was resistant to all races. Cultivars also varied in their race-non-specific (horizontal) resistance: cultivars that were susceptible to particular races usually varied in their degree of susceptibility to those races. In particular, Junee was more resistant to all four races than the other cultivars within its group. Similarly, cultivars Gosse, Larisa, Denmark and Trikkala were more resistant to races 1 and 3 than the other cultivars in their group. Races of the pathogen varied in their aggressiveness as well as in their virulence, as shown by the variation in aggressiveness of different isolates of race 0.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 42
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 92 (1996), S. 81-87 
    ISSN: 1573-5060
    Keywords: barley ; net blotch ; Pyrenophora teres ; resistance ; Hordeum vulgare
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Seedlings of a differential barley (Hordeum vulgare L.) series (21 genotypes) and of six check genotypes were used in the greenhouse to assess variation in virulence among 20 single-spore isolates of the net blotch pathogen. Pyrenophora teres Drechs. f.teres Smedeg., collected from various sites in Finland. The experiment was run twice and symptom expression was recorded on the first three leaves. Analysis of second leaf symptom scores from Run 1 indicated differences in virulence between isolates, all of which were pathogenic, and differential resistance among the barleys. The virulence of P. teres isolates appeared to be conditioned by the host barley from which the isolate derived; the average virulence of isolates collected from a susceptible host was greater than that of isolates collected from a less susceptible host. Results from Run 2 were similar regarding resistance within the barleys, but variation in virulence among the P. teres isolates was not consistent with that from Run 1. CI 9819 caries duplicate genes for resistance to P. teres (Rpt1b and Rpt1c), and CI 7548 possesses Rpt3d. Both genotypes were highly resistant to all isolates. The Rpt1a gene of Tifang (CI4407) conferred resistance to all isolates in Run 2, but only to about half of the isolates in Run 1. The checks, including two of the symptomatically most resistant Nordic barley genotypes, were universally susceptible during these stringent tests. No selective pressure has been placed on Finnish isolates of P. teres through previous deployment of major resistance genes, and it is speculated that any variation in virulence among isolates is likely to be due to a combination of evolutionary forces including, natural selection, random genetic drift and gene flow.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 43
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 93 (1997), S. 353-360 
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; Secale cereale ; powdery mildew ; Erysiphe graminis f.sp. tritici ; resistance ; suppression ; segregation distortion ; wheat ; rye
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The location of wheat gene Pm8 for resistance to powdery mildew in the 1RS chromosome segment derived from cereal rye cultivar Petkus was confirmed. There was reduced transmission of the 1BL.1RS chromosome relative to its wheat homologue in four of the five crosses examined. Pm8 was not expressed in some wheat cultivars and selections which possessed the 1RS chromosome identified by the presence of relevant genes for resistance to the three rusts, due to the presence of a dominant suppressor gene(s) in the wheat genome. The frequency of suppression in 1BL.1RS wheats from Mexico was significantly higher than in a group of wheats (both local and exotic) introduced from China and was probably much higher than in European wheats.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 44
    ISSN: 1573-5060
    Keywords: Allium porrum ; autotetraploidy ; introgression ; Phytophthora porri ; resistance ; screening methods ; leek
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A new screening method was developed to evaluate resistance of leek (Allium porrum) to Phytophthora porri, based on inoculation by 24 h-immersion of leek plantlets in the 3–6 leaf stage in a suspension of ca. 100 zoospores.ml-1. The immersion test was used for identifying new sources of resistance and to determine the genetic basis of resistance. Within winter leek, five resistance classes were defined on the basis of average field scores of 21 plants. Clones from these plants were tested with the immersion technique. The average scores per resistance class in immersion and field tests were significantly correlated (P〈0.01). The correlation of single-date field scores with the immersion test scores was better in the second half of the epidemic season. A selection experiment yielded a strong response to selection for resistance (53–97%) but no response to selection for susceptibility. This may indicate that resistance is due to few recessive genes in the studied winter leek. Crosses between landraces and winter leek were analyzed by means of F2 (selfed F1) and BC1, progenies. This analysis indicated the presence of few loci with dominant genes for resistance in accession CGN 873243, and additive polygenes in accession Pl 368351.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 45
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 94 (1997), S. 31-36 
    ISSN: 1573-5060
    Keywords: Triticum ; Fusarium graminearum ; resistance ; head scab ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Multi-floret and single-floret injection inoculation methods were used to test 1076 accessions of Triticum for resistance to initial infection and resistance to pathogen spread within spike tissue respectively. The data obtained between years or inoculation dates were comparatively similar and were little influenced by climatic factors, especially humid condition. All the tested materials uniformly exhibited susceptibility to initial infection, but there were great differences in resistance to spread among species or cultivars. The diploid and tetraploid wheats were severely susceptible. Only 30 genotypes of common wheat of T. aestivum concv. vulgare showed high resistance to spread. The highest frequency of high spread resistance existed in these landraces which were distributed in Zhejiang, Hubei, Hunan, Jiangsu provinces and Shanghai City, Guizhou, Sichuan and Yunnan provinces ranked second. The majority of wheat landraces from Hebei, Shanxi, Shaanxi Province and Beijing City showed susceptibility or high susceptibility. No resistance was found in Tibetian wheats.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 46
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 94 (1997), S. 69-73 
    ISSN: 1573-5060
    Keywords: foxtail millet ; herbicide ; resistance ; interspecific hybridization ; sethoxydim ; inheritance ; Setaria italica
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Interspecific hybridization between foxtail millet cultivars (Setaria italica) and a green foxtail (S. viridis) resistant to the herbicide sethoxydim were undertaken to breed foxtail millet for improved herbicide resistance. Parents, reciprocal F1 hybrids, F2 selfed derived populations and BC1 backcross progeny were produced and analysed for mortality and fresh weight over a range of dosages. All resistant progeny were 700 times more resistant than susceptible cultivars and was symptom free under current field dosages. Segregations of resistant and susceptible progeny (3:1 in F2 and 1:1 in BC1) were not dependent upon dosage. Heterozygous individuals displayed the same magnitude of resistance as homozygous plants at twelve times the recommended field dosage. Results suggested that sethoxydim resistance in foxtail millet was controlled by a single, completely dominant, nuclear gene.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 47
    ISSN: 1573-5060
    Keywords: Cucumis sativus ; Frankliniella occidentalis ; plant age ; leaf position ; reproduction ; resistance ; cucumber ; western flower thrips
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Three greenhouse cucumber (Cucumis sativus L.) accessions, previously selected for low levels of damage after infestation with Frankliniella occidentalis (Pergande), were tested for resistance against F. occidentalis in a no-choice greenhouse experiment at the mature plant stage. The three accessions showed a strong reduction in thrips damage compared to the susceptible control. The effects of leaf position and plant age of the four cucumber accessions on the reproduction of F. occidentalis were determined in a leaf disc assay. Leaf position had a significant effect on thrips reproduction, whereas plant age, within the test range, had not. In general, reproduction was higher on young leaves. Reproduction as measured on leaf discs from certain leaf positions was strongly correlated with resistance of mature plants in the greenhouse, and can therefore be used as a quick test to screen cucumber accessions for resistance against thrips.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 48
    Electronic Resource
    Electronic Resource
    Springer
    Genetic resources and crop evolution 43 (1996), S. 569-574 
    ISSN: 1573-5109
    Keywords: bacterial wilt ; germplasm evaluation ; Lycopersicon esculentum ; Pseudomonas solanacearum ; resistance ; tomato
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Seedlings of two hundred and thirty-three accessions of the tomato collection maintained at the Centro Agronómico Tropical de Investigación y Enseñanza, Turrialba, Costa Rica (CATIE) and 7 cultivars used as controls were evaluated for host-plant resistance to 4 virulent strains of Pseudomonas solanacearum representing race 1 biovars 1 and 3. In general, biovar 3 strains wilted seedlings faster than biovar 1 strains but, after 20 days post-inoculation, no significant differences were noted in susceptible control ratings. Significant differences for disease index were noted, but no line with complete resistance was found. For the USA biovar 1 strain UW-25, only 5 accessions, CATIE 17331, 17334, 17349, 17739, 17740, and 2 of the control cultivars, ‘Hawaii 7998’ and ‘UC-82B’ showed some degree of resistance. Conversely, both the frequency and the degree of resistance were high for Costa Rican biovar 1 strain UW-256. For biovar 3, the Costa Rican strain UW-255 was more virulent than the Peruvian strain UW-130. Eight CATIE accessions, 5539, 17331, 17333, 17334, 17345, 17349, 17742, and MIP-CH1, were as resistant as the resistant control ‘Hawaii 7998’ to 3 strains and accession 17740 was as resistant as ‘Hawaii 7998’ to all 4 strains.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 49
    Electronic Resource
    Electronic Resource
    Springer
    Genetic resources and crop evolution 43 (1996), S. 79-84 
    ISSN: 1573-5109
    Keywords: Cucurbita pepo ; squash ; genetic resources ; Erysiphe cichoracearum ; cucurbit powdery mildew ; resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Fifty-eight cultivars of Cucurbita pepo (mostly zucchini type) were studied in three-year experiments for field resistance to powdery mildew caused by Erysiphe cichoracearum. No genotypes were found with complete resistance to powdery mildew. There were significant differences in the expression of field resistance characterized by some basic epidemiological parameters (maximum infection degree, area below curve). The highest level of field resistance occurred in 13 cultivars including Acceste F1, Albina, ambassador F1, CU-235, Elite F1, Goldfinger, Parmanta F1, Seneca Hybr. F1.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 50
    ISSN: 1573-5109
    Keywords: antibiois ; Mayetiola destructor ; resistance ; Triticum turgidum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Hessian fly, Mayetiola destructor (Say), is the major pest of wheat in North Africa. In Morocco, durum wheat (Triticum turgidum L. subsp. durum (Desf). Husn.) losses due to this pest have been estimated at 32%. Genetic resistance is the only economical and practical means of controlling this insect. Field and greenhouse screening of durum wheat genotypes resulted in the identification of one source of resistance to Hessian fly in Morocco. This is the first source of durum wheat Hessian fly-resistance identified in Morocco. This source of resistance expresses a medium level of antibiosis against first-instar Hessian fly larvae; about 25% of the larvae survive on resistant plants. The deployment of varieties that allow for larval survival on resistant plants should reduce selection for biotype development. This source of resistance is being used by CIMMYT/ICARDA and Moroccan breeders to develop resistant durum wheat varieties.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 51
    Electronic Resource
    Electronic Resource
    Springer
    Genetic resources and crop evolution 42 (1995), S. 371-372 
    ISSN: 1573-5109
    Keywords: bacterial blight ; interspecific hybridisation ; Matthiola ; resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Accessions ofM. tricuspidata (L.) R. Br.,M. aspera Boiss. andMatthiola longipetala (Vent.) DC. were tested for their reaction to bacterial blight of stock (M. incana R. Br.), caused byXanthomonas campestris pv.incanae. Potted plants were sprayed with bacterial cell suspension, adjusted to 108 cells/ml. The tested accessions of the three species were found highly resistant, while control plants ofM. incana were severely infected. InterspecificF 1 hybrid plants betweenM. incana andM. tricuspidata also exhibited high resistance to the disease. The implications and the expected difficulties in breeding stock for bacterial blight resistance are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 52
    ISSN: 1573-5109
    Keywords: Aegilops ; antibiosis ; Mayetiola destructor ; Morocco ; resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Hessian fly, Mayetiola destructor (Say), is the major insect pest of wheat in Morocco. Host plant resistance has been the most effective and practical method of controlling this pest. When 347 accessions of Aegilops species were screened in the greenhouse for resistance to Hessian fly, several accessions of Ae. geniculata Roth, Ae. triuncialis L., Ae. neglecta Req.ex Bertol., Ae. ventricosa Tausch, Ae. cylindrica Host and Ae. markgrafii (Greuter) Hammer showed resistance reaction. All expressed antibiosis as the mechanism of resistance against first instar Hessian fly larvae. These Aegilops sources of resistance could be exploited for transferring Hessian fly resistance to wheat.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 53
    Electronic Resource
    Electronic Resource
    Springer
    Genetic resources and crop evolution 44 (1997), S. 271-275 
    ISSN: 1573-5109
    Keywords: Cucumis spp. ; germplasm evaluation ; wild progenitors ; Pseudomonas syringae pv. lachrymans ; artificial inoculation ; seedlings ; necrotization ; resistance ; gene centers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Under controlled inoculation, a set of 49 accessions belonging to 16 wild species and varieties of the genus Cucumis was tested for resistance to Pseudomonas syringae pv. lachrymans. There was no complete resistance to this pathogen in Cucumis accessions, but limited necrotization of leaves was observed in four accessions (C. africanus (PI 203974), C. anguria var. longipes (CUC 28/1974), C. melo subsp. conomon Baj-Gua (CUM 238/1974), C. zeyheri (PI 299572)). There were some quantitative differences between Cucumis accessions in disease symptom development.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 54
    Electronic Resource
    Electronic Resource
    Springer
    Genetic resources and crop evolution 42 (1995), S. 1-6 
    ISSN: 1573-5109
    Keywords: Barley ; Hordeum vulgare ; Hordeum spontaneum ; leaf rust ; Puccinia hordei ; resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract An isolate ofPuccinia hordei (ND89-3) originally collected in Morocco is virulent on most barley genotypes reported to possess resistance, except cultivar Estate (CI 3410), which possesses theRph3 gene and exhibits a low to intermediate level of resistance (infection type 12). Isolate ND89-3 possesses one of the widest virulence spectrums reported forP. hordei. Accessions ofHordeum vulgare (1,997 in total) andH. spontaneum (885 in total), mostly originating from the Mediterranean region and parts of North Africa, were evaluated with isolate ND89-3 at the seedling stage to identify new sources of leaf rust resistance. Fifty-eight accessions ofH. vulgare, and 222 accessions ofH. spontaneum exhibited low infection types to this isolate. Further evaluations of these resistant accessions with isolates ofP. hordei virulent forRph3,Rph7, andRph12 suggested that most of the resistantH. vulgare accessions possess theRph3 gene. Data suggested additional sources of effective resistance inH. vulgare are rather limited. FiveH. vulgare accessions and 167H. spontaneum accessions were identified as possible sources of new genes for leaf rust resistance. These accessions likely possess resistance genes that are different fromRph1 toRph12, or gene combinations thereof based on their reaction to four leaf rust isolates. Utilization of these accessions in barley breeding will broaden the germplasm resources available for genetic control ofP. hordei.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 55
    Electronic Resource
    Electronic Resource
    Springer
    Genetic resources and crop evolution 44 (1997), S. 439-445 
    ISSN: 1573-5109
    Keywords: Germplasm ; Meloidogyne ssp. ; red clover ; resistance ; root-knot nematode ; Trifolium spp.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A germplasm collection of red clover (Trifolium pratense L.) and seven related species was evaluated in greenhouse tests for resistance to Meloidogyne arenaria (Neal) Chitwood, M. hapla Chitwood, M. incognita (Kofoid & White) Chitwood, and M. Javanica (Treub) Chitwood. Plants were rated for root galling severity and nematode egg production at eight weeks after inoculation with 1500 nematode eggs. A resistance index, RI = √(gall2; + egg2;), was generated to assess the plants' reaction to nematode infection as immune, highly resistant, resistant, moderately resistant, intermediate, moderately susceptible, susceptible, or highly susceptible. More than 98% of red clover accessions were intermediately to highly susceptible to all four root-knot nematode species. Only one accession, PI 271627 introduced from India, had a moderate resistance level to the four nematodes tested. About one third of the T. medium accessions were resistant or highly resistant to M. arenaria, M. incognita, and M. javanica whereas more than 50% of the T. alpestre accessions were highly resistant or immune to all four nematodes species. Genetic factors for resistance to root-knot nematode could be introduced into T. pratense through interspecific hybridization with T. medium and/or T. alpestre
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 56
    Electronic Resource
    Electronic Resource
    Springer
    Genetic resources and crop evolution 46 (1999), S. 469-475 
    ISSN: 1573-5109
    Keywords: foliar blight ; germplasm ; resistance ; Triticum aestivum ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract One thousand three hundred and eighty-seven spring wheat germplasm (Triticum aestivum L.) lines belonging to the Indian and CIMMYT wheat programmes were evaluated for their tolerance to foliar blight disease for three consecutive years i.e., from 1994 to 1997. Disease severity at six different growth stages, beginning from tillering to late milk stage, was recorded. None of the genotypes showed immunity to the disease. Of 43 lines showing resistant reaction, a major proportion (25) was represented by CIMMYT material. Comparatively, Indian germplasm lines tended to be more susceptible at more advanced growth stages. Area Under Disease Progress Curve (AUDPC) and Apparent Infection Rate (r) values of resistant lines were much lower than those of susceptible ones, but lower AUDPC in some of the resistant lines did not correspond to a lower 'r' value. Most of the resistant lines were derived from Seri, Myna, Bau, kauz, Hork 's' and Aegilops tauschii Coss.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 57
    Electronic Resource
    Electronic Resource
    Springer
    Genetic resources and crop evolution 46 (1999), S. 557-568 
    ISSN: 1573-5109
    Keywords: Arachis spp. ; Meloidogyne javanica ; resistance ; root-knot nematodes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The root-knot nematode, Meloidogyne javanica Race 3 is an important nematode parasite of groundnut. Greenhouse evaluation of 184 accessions of 33 wild Arachis spp. five interspecific derivatives, 18 groundnut cultivars for root damage (galls formed by nematode) and nematode reproduction demonstrated that resistance to the nematode is available in the genepool of wild Arachis spp. Seven accessions, ICG 8952 (Arachis helodes), ICC 13211 (A. sylvestris), ICG 13224 (A. kretscmeri), ICG 13231 (Arachis sp.), ICG 14862 (A. kuhlmannii), ICG 14868 (A. stenosperma), and ICG 14915 (A. sylvestris) were highly resistant to nematode reproduction and root damage. There was no gall and eggmass formation on any plant of these accessions. Thirty-three accessions were resistant and 14 were moderately resistant. All the tested accessions of A. monticola, A. benensis, A. ipaensis, A. hoehnei, A. kempff-mercadoi, A. valida, A. chiquitana, A. rigonii, A. vallsii, A. dardani, A. paraguariensis, A. triseminata, interspecific derivatives, and groundnut cultivars were susceptible. The possible use of resistance sources in the breeding program is discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 58
    Electronic Resource
    Electronic Resource
    Springer
    Genetic resources and crop evolution 43 (1996), S. 461-469 
    ISSN: 1573-5109
    Keywords: Cucurbita ssp. ; germplasm evaluation ; cucumber mosaic virus ; artificial inoculation ; seedlings ; local and systemic infection ; resistance ; centers of origin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary A total of 384 Cucurbita pepo and Cucurbita maxima accessions were evaluated in growth chambers or glasshouse tests for resistance to cucumber mosaic virus (CMV). Seedlings were mechanically inoculated at the cotyledon stage, and scored for symptoms on cotyledons and true leaves 7 and 18 days after inoculation. Significant variation in resistance was found. A limited number of accessions were free of visual symptoms of infection. One C. pepo accession and thirteen C. maxima accessions showed a high level of resistance. Generally, C. maxima may be considered more resistant to CMV compared to C. pepo. There is no close relationship between origin, fruit morphotypes and CMV resistance in either species. Some accessions (e.g., C. pepo PI 438699; C. maxima PI 176530, PI 265555, PI 368564, PI 500483) could be useful for the future breeding programmes. The C. pepo cvs. ‘Cinderella’ and ‘Defender’ F1, previously described as resistant, showed maximum susceptibility to the yellow strain of CMV.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 59
    Electronic Resource
    Electronic Resource
    Springer
    Agroforestry systems 45 (1999), S. 215-244 
    ISSN: 1572-9680
    Keywords: biodiversity ; disturbance ; nitrogen ; phosphorus ; resilience ; resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Nutrient and hydrologic cycles in harvested native forests in southern Australia are largely balanced. For example, we have little or no evidence of any decline in nutrient capital or availability in harvested forests. Short-term and small-scale reductions in evapotranspiration due to loss of leaf area after harvesting are adequately balanced at the landscape scale by large areas of regenerating or older-age forest. In contrast, agricultural systems on similar soils are a) dependent on large inputs of fertilisers to maintain growth and b) frequently subject to increasing salinity and waterlogging or other forms of degradation. The large-scale replacement of long-lived communities of perennial and often deep- rooting native species with annual crops or other communities of shallow-rooting species might be better managed within the framework of knowledge developed from studies of native plant communities. However, application of such a mimic concept to systems of low natural productivity is limited when agricultural systems require continued high productivity. Nonetheless, the mimic concept may help in developing sustainable management of agriculture on marginal lands, and contribute to the nutritional resilience of agroecosystems. Relevant characteristics for mimic agroecosystems in south western Australia include: high species diversity, diversity of rooting attributes, utilisation of different forms of nutrients (especially of N and P) in space and time, and the promotion of practices which increase soil organic matter content.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 60
    Electronic Resource
    Electronic Resource
    Springer
    Genetic resources and crop evolution 43 (1996), S. 103-107 
    ISSN: 1573-5109
    Keywords: resistance ; Cicer ; Hetrodera ciceri ; chickpea ; wild species
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Among the nematodes infesting chickpea (Cicer arietinum L.) plants in Syria, cyst nematode (Heterodera ciceri Vovlas, Greco et Di Vito) is the most important. It is uneconomical to grow chickpea in fields infested with cyst nematode and to control this nematode with nematicide. Therefore, investigations were conducted at ICARDA, Syria from 1987 to 1991 to identify sources of resistance to cyst nematode in 7258 lines of C. arietinum and 102 lines of eight annual Cicer species including C. bijugum K.R. Rech. (13 lines), C. chorassanicum (Bge) M. Pop. (3 lines), C. cuneatum Hochst. ex Rich. (3 lines), C. echinospermum P.H. Davis (8 lines), C. judaicum Boiss. (18 lines), C. pinnatifidum Jaub. & Sp. (18 lines), C. reticulatum Ladiz. (36 lines), and C. yamashitae Kitamura (3 lines). All lines were grown in a greenhouse at 15–25°C in pots containing soil infested with 20 eggs of the nematode g-1 soil. Nematode infestation was evaluated on a 0 to 5 scale based on number of females and cysts on roots. Resistance was found in one line of C. bijugum, six lines of C. pinnatifidum, and one line of C. reticulatum. No lines of C. arietinum, C. chorassanicum, C. cuneatum, C. echinospermum, C. judaicum, or C. yamashitae was resistant to cyst nematode. Plants with resistance have been recovered in the F3 generation from crosses between the cultigen and C. reticulatum, indicating the possibility of transfer of gene(s) for resistance to cyst nematode from wild to cultivated Cicer species.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 61
    Electronic Resource
    Electronic Resource
    Springer
    Genetic resources and crop evolution 43 (1996), S. 257-259 
    ISSN: 1573-5109
    Keywords: resistance ; iron-deficiency ; chickpea ; germplasm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Iron-deficiency chlorosis is often seen in chickpea (Cicer arietinum L.) fields in the Mediterranean region and is particularly severe in fields where iron-deficiency susceptible cultivars are sown. Therefore, ICARDA's breeding programme field evaluated 6224 kabuli chickpea germplasm accessions for iron-deficiency chlorosis on a high pH Calcic Rhodoxeralf soil (pH 8.5, 20–25% calcium carbonate) at Tel Hadya, Syria during the winter and spring of 1987/88. Two resistant and 17 susceptible lines were grown during autumn, winter and spring of 1988/89 to examine the effect of sowing time on the appearance of the deficiency. About 99% of accessions showed no iron-deficiency symptoms. Evaluation of susceptible accessions during autumn, winter, and spring sowing revealed that iron-deficiency chlorosis was more pronounced during winter sowing. There were also significant genotype x season interactions, indicating differential responses of genotypes to time of sowing. Since the iron-deficiency chlorosis character is controlled by recessive genes, a negative selection to discard the susceptible lines from breeding material is recommended as an effective breeding strategy.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 62
    Electronic Resource
    Electronic Resource
    Springer
    Genetic resources and crop evolution 44 (1997), S. 211-215 
    ISSN: 1573-5109
    Keywords: Fusarium graminearum ; resistance ; Roegneria ; scab ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract 71 accessions from 13 Roegneria species were evaluated for resistance to wheat scab. The results showed that 31 of the 71 accessions possessed high resistance (HR) to initial infection and high resistance (HR) to pathogen spread. The disease spread from inoculated floret to head rachis was not observed, and the incidence of head infection were lower under natural than under artificial inoculation conditions. The intergeneric hybrid F1 of Roegneria tsukushiensis (Honda) B.R. Lu, Yen et J.L. Yang. var. transiens (Hack.) B.R. Lu, Yen et J.L. Yang × Hordeum vulgare Linn. exhibited resistance (R) to pathogen invasion and high resistance (HR) to spread. Therefore, Roegneria could be used as scab resistant resources in cereal breeding. In addition, the relatioship between its resistance and ecological environments where Roegneria was distributed was discussed in this paper.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 63
    Electronic Resource
    Electronic Resource
    Springer
    Genetic resources and crop evolution 46 (1999), S. 163-168 
    ISSN: 1573-5109
    Keywords: Vavilov ; centres of diversity ; America ; Solanium ; potatoes ; resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Vavilov's ideas on New World centres of crop plant diversity are reviewed and the development of his ideas from 1926 to 1940 are described. More recent collecting work and taxonomic studies by the author confirm largely the delimitation of the American gene centres suggested by Vavilov, even in regard to details, e.g. within Bolivia.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 64
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; Heterodera avenae ; resistance ; breeding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Breeding wheat for resistance to Heterodera avenae in southern Australia has been in progress for nearly 30 years and recently a number of resistant varieties have been released. Early breeding work was hampered by three factors: • a lack of appreciation of the role and extent of the problem, • inaccurate, slow screening methods, ultimately being replaced by the 'tube' test and soon by linked molecular markers, • inappropriate breeding strategies, so that varietal releases have taken place only when the breeding has been fully integrated into the main programs. The experiences in southern Australia will be relevant to many other areas in the world where H. avenae is the major pest.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 65
    ISSN: 1573-5060
    Keywords: Bemisia tabaci ; inoculation techniques ; Lycopersicon spp. ; resistance ; TYLCV
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract For two consecutive years nine hybrids and three varieties of tomato, four Lycopersicon peruvianum and four Lycopersicon chilense accessions were screened for Tomato yellow leaf curl virus (TYLCV) resistance. Three inoculation techniques using Bemisia tabaci, the vector of TYLCV, were compared: (1) artificial mass inoculation-simultaneous infection of cultivated and wild material in greenhouses; (2) artificial cage inoculation-individual infection in insect-proof cages; (3) natural field infection. Artificial inoculations led to higher levels of infection, but different patterns of response to each inoculation technique were found depending on the resistance level. Tomato varieties showed an important fruit set reduction after both artificial and natural inoculations. In contrast, field infection was milder in tomato hybrids, in which yield was barely affected. These hybrids showed a wide range of reactions with the two artificial inoculation techniques, but infection was always more severe after mass inoculation. Extreme severity of mass infection made it difficult to differentiate among variable degrees of resistance that were more reliably detected with cage inoculation. The hybrids F3524, F3522, Fiona, and Tyking showed the highest level of resistance. F3524 and F3522 had an acceptable yield in field and cage assays, but their resistance collapsed under massive conditions of infection. Tyking and Fiona exhibited the best response in all conditions, although their yield was moderately reduced in mass assays. Mass inoculation was not adequate for the screening of wild Lycopersicon. Some susceptible plants escaped infection, probably as a consequence of non-preference mechanisms and loss of vector infectivity. Individual inoculation in cages prevented the risk of non-infection, ensuring 100% disease incidence. This technique allowed the selection of highly resistant wild sources. L. chilense LA 1969 and LA 1963 had the highest level of resistance with the three inoculation techniques. L. peruvianum PI-126944 and L. chilense LA 1932, which were only tested in mass and field conditions, also exhibited a promising response. The results proved that the inoculation technique influences the response of tomato and wild Lycopersicon spp to TYLCV. It is concluded that artificial cage inoculation, although more time-consuming, is the most efficient, adequate, and reliable technique to screen both cultivated and wild Lycopersicon species for resistance to TYLCV.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 66
    ISSN: 1573-5060
    Keywords: Fusarium subglutinans ; callus ; tissue culture ; culture filtrate ; resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Two pineapple varieties differing in resistance to fusariose were examined for the phytotoxic effect of Fusarium subglutinans culture filtrate. The cultivars were Perolera (more resistant to pathovars of Fusarium subglutinans) and Smooth Cayenne (more susceptible). The phytotoxic effect of culture filtrate was assessed in tissue culture pineapple plantlets (by electrolyte leakage and placing the culture filtrate on wound leaf segments) and callus (inhibition of growth). Smooth Cayenne proved to be the most sensitive cultivar in each test, whereas Perolera showed resistance to the culture filtrate and its callus grew in the presence of high concentrations of culture filtrate that were completely toxic to Smooth Cayenne. These results show that plants can display cellular resistance to the culture filtrate.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 67
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 107 (1999), S. 71-78 
    ISSN: 1573-5060
    Keywords: Russian wheat aphid ; resistance ; inheritance ; allelism ; segregation ratio ; wheat ; Triticum aestivum L.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko), is an important pest of wheat (Triticum aestivum L.) in the United States of America. Developing adapted wheat cultivars with genetic resistance to RWA is an effective control strategy. Genetic studies were conducted to determine the mode of inheritance of gene(s) conferring resistance to RWA in an Iranian landrace wheat line, G 5864. For the inheritance study, G 5864 was crossed with the susceptible wheats ‘Yecora Rojo’ and ND 2375. Seedlings of F1, reciprocal F1, F2, BC1 to the susceptible parent (BCS), and BC1 to the resistant parent (BCR) were screened for RWA reaction. Several phenotypic segregation ratios were tested in the F2 populations for goodness of fit; the 9:3:3:1 ratio (resistant: rolled leaves: stunted plants: susceptible) was an acceptable fit in all cases. Thus, resistance in G 5864 seemed to be controlled by two independent dominant genes with additive gene effects. The allelic relationships of gene(s) in this line with genes in other resistant lines, PI 137739 (Dn1), PI 262660 (Dn2), PI 372129 (Dn4), PI 294994 (Dn5), and PI 243781 (Dn6), were also studied. Segregation patterns observed in G 5864 × resistant (R × R) F2 populations were inconclusive. However, no susceptible plants were observed in these F2 populations. If previous reports concerning the number of resistance genes present in the other resistant lines are correct, then given the high manifestation of resistance observed in G 5864, and given the absence of susceptible plants in the R × R F2 populations, it is indicated that RWA resistance in G 5864 is either controlled by different alleles at the same loci as the other resistance genes, or that G 5864 shares a resistance gene with each of the other resistant lines.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 68
    ISSN: 1573-5060
    Keywords: disease assessment ; maturity ; resistance ; Septoria tritici ; Triticum aestivum ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Nineteen cultivars, with large differences in heading date, were evaluated for their response to septoria tritici blotch in two experimental setups in Njoro, Kenya. Due to the more or less constant temperatures during the growing season and the overhead irrigation applied the epidemic conditions were similar over the whole observation period for the early and late cultivars. In experiment 1 the cultivars were assessed for disease severity at the same moment irrespective of the developmental stage, while in experiment 2 the cultivars were assessed at the same developmental stage. Measured at the same time, the disease severity was highest in the early maturing cultivars and lowest in the late maturing cultivars (r = –0.78). When assessed at the same development stage the disease build up was independent of heading date (r = –0.10) but strongly dependent on resistance level. There were no indications that early heading cultivars were more susceptible than late heading cultivars.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 69
    ISSN: 1573-5060
    Keywords: Mentha piperita ; peppermint ; resistance ; somaclone ; verticillium wilt
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Three studies were initially conducted using five mint cultivars with known disease reactions to verticillium wilt to determine if inoculation method, root-dip as compared to root-injection, had an affect on the plant growth and disease reaction. The planting media did not affect the development of wilt symptoms in susceptible varieties, however, the soil/peat based medium resulted in higher shoot fresh weight at harvest than the perlite/vermiculite medium. Black Mitcham had the highest susceptible disease rating and greatest reduction in fresh shoot weight from inoculation with Verticillium dahliae at two inoculum concentrations, 104 or 106 microconidia/ml. Native spearmint was resistant and Mentha crispa was moderately resistant, whereas, Murray Mitcham peppermint and Scotch spearmint were moderately susceptible to verticillium wilt with a corresponding lower fresh shoot weight. Scotch spearmint was less susceptible at the low inoculum concentration than at a higher level of microconidia, indicating a low level of disease resistance. Overall, the two inoculation methods resulted in similar cultivar responses to verticillium wilt, although the root-injection method was more applicable for large plant populations. Thus, the root-injection method of inoculation was utilized to screen 743 Black Mitcham derived somaclones for wilt resistance, of which nine somaclones were found resistant in repeated inoculation tests.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 70
    ISSN: 1573-5060
    Keywords: bacterial wilt ; inoculum concentration ; potato ; Pseudomonas solanacearum ; resistance ; Solanum tuberosum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Potato plantlets derived from in vitro propagation of three cultivars known for their field resistance (Cruza 148 and BR-63.65) or susceptibility (Désirée) to Pseudomonas solanacearum E.F. Smith were artificially inoculated under controlled conditions. The aim of this work was to determine the optimal inoculum concentration and the best observation period in which the cultivars would show different reactions to bacterial infection as expected on the basis of their field performance. A suitable statistical analysis of disease indices is proposed to distinguish between resistant and susceptible responses, with a particular care for the applicative needs and a univocal interpretation of the results. In order to evaluate the significance of sources of variation related to the observed mean differences, the analysis of variance and a convenient clustering procedure of disease index means were applied. The statistical analysis revealed that, under our conditions, an inoculum concentration of 5×106 cfu/plant was suitable for separating resistant from susceptible responses, in accordance with the reactions already observed in field experiments by other authors. Also, differences among the three cultivars were best observed nine to twelve days after inoculation with the pathogen.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 71
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 81 (1995), S. 71-77 
    ISSN: 1573-5060
    Keywords: Chinese cabbage (Brassica campestris subsp. pekinensis) ; turnip mosaic virus ; resistance ; monoclonal antibody
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Inheritance of resistance to turnip mosaic virus (TuMV) strains C1, C2, C3, C4, and C5 in Chinese cabbage (Brassica campestris subsp. pekinensis) was evaluated using monoclonal antibodies. Crosses were made between a resistant line, ‘0–2’, and four susceptible line. ‘Seoul’ (SE),‘SSD31’ (SS), ‘Cheongbang’ (CH), and ‘Yaki 1 ho’ (YA), to determine the inheritance of resistance of ‘0–2’ in different genetic backgrounds. Resistance to TuMV was controlled by a single dominant gene or double dominant genes depending on the strain and cross. The resistance genes of ‘0–2’ were modified by susceptible parents such that a single dominant gene was involved in the ‘SS×0–2’ combination, but double dominant genes in the ‘SE×0–2’ against TuMV-C3 or TuMV-C5. ELISA tests using inoculated and noninoculated leaves in the same plant suggested that the dominant resistance genes inhibit virus movement rather than virus multiplication.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 72
    ISSN: 1573-5060
    Keywords: Capsicum annuum ; chili pepper ; resistance ; Scirtothrips dorsalis ; sweet pepper ; thrips
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary A preliminary evaluation for resistance to chili thrips, Scirtothrips dorsalis Hood of 41 and 194 pepper (Capsicum annuum L.) germplasms during 1987 and 1988, respectively, indicated chili accessions may be a promising source of resistance. In contrast, all sweet pepper accessions tested were highly susceptible. A number of chili accessions produced a moderate yield, in spite of a high thrips infestation indicating tolerance to S. dorsalis. Rating for thrips damage was more reliable and efficient than estimating thrips numbers in screening pepper accessions for resistance to thrips. Highly significant, positive correlation between ratings at the seedling stage and final rating for thrips damage indicated the feasibility of screening pepper accessions at the seedling stage. Comparing the similarities in rating among accessions resulted in 40 distinct groups. The variance-covariance matrix of the data from these 40 groups was subjected to principal component analysis. This accounted for 56 and 18 per cent of the variation across the two principal axes, respectively. Projection of chili and sweet pepper accessions along these two axes revealed three distinct clusters. About 80 per cent of chili accessions formed the first cluster, 58 per cent of the sweet pepper accessions formed the second cluster and a third cluster exhibited intermediate ratings for thrips damage. The significance of these findings in relation to geographical divergence and resistance to thrips among pepper accessions is discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 73
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 97 (1997), S. 227-233 
    ISSN: 1573-5060
    Keywords: Erysiphe graminis f.sp. hordei ; genetic resources ; Hordeum vulgare ; recurrent selection ; resistance ; virulence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A total of 4,681 accessions of Hordeum vulgare landrace material from Ethiopia, East Mediterranean, Near East, Nepal and China were sown in the field and subjected to the natural powdery mildew epidemic in Denmark. Apparently resistant accessions were selected. Selfed progeny from them were retested and reselected in subsequent years at four locations in Denmark. Finally, 16 promising donors of resistance were retained. They were characterized in the field and tested in the seedling stage for reaction to up to 72 different isolates of the powdery mildew fungus. The absence of the corresponding virulences in the Danish airborne powdery mildew population was ascertained in five years. The resistances in the 16 donors are apparently mutually different and from known sources of powdery mildew resistance in barley.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 74
    ISSN: 1573-5060
    Keywords: arabica coffee ; coffee berry disease ; marker ; random amplified polymorphic DNA ; resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Resistance to Coffee Berry Disease (CBD) in Arabica coffee is controlled by at least three genes which are present in the varieties Hibrido de Timor (T gene), Catimor (T gene), Rume Sudan (R and k genes) and K7 (k gene). Hibrido de Timor, Catimor and Rume Sudan are genetically distant from most of the commercial cultivars, and the utilisation of molecular markers would greatly improve the efficiency of breeding programmes concerned with CBD resistance. The objectives of the present work were therefore: (1) to identify random amplified polymorphic DNA (RAPD) markers associated with CBD resistance and (2) to identify markers which could be used to select against the genetic background of the resistance donors. Identification of RAPD markers was carried out in three steps. The first step involved the comparison of the RAPD profiles between the susceptible cultivars and the resistant donors. This was followed by comparison of the RAPD profiles between resistant and susceptible types of each donor variety. The final step involved assay of the resistance markers in the first and the second backcrosses between these donors and the recurrent parent. High genetic variability was demonstrated in Catimor, and to some extent in Rume Sudan. Three RAPD markers were shown to be closely associated to the T gene. Attempts to identify markers associated with the R and k genes were less rewarding. The implications of the current observations in relation to breeding for CBD resistance in Arabica coffee are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 75
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 98 (1997), S. 69-74 
    ISSN: 1573-5060
    Keywords: Fusarium oxysporum f.sp. lentis ; lentil ; resistance ; vascular wilt
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Host-plant resistance is the best means to control the key disease of lentil-vascular wilt, caused by Fusarium oxysporum Schlecht. emend. Snyder & Hansen f.sp. lentis Vasudeva and Srinivasan. Systematic screening for resistance to lentil wilt was initiated in the field in 1993, in a wilt-sick plot in North Syria, with a core collection of 577 germplasm accessions from 33 countries. A subset (88 accessions) of mostly resistant accessions was re-screened in 1994. The most resistant accessions came from Chile, Egypt, India, Iran and Romania. Variation among accessions in the temporal pattern of wilting was analyzed. The limited wilting in resistant accessions followed a linear model through time, whereas the pattern for susceptible accessions was better described with an exponential model. This temporal variation emphasizes the need for repeated scoring during screening for resistance to lentil vascular wilt to identify ‘late-wilters’. To overcome spatial variation in inoculum density, the efficacy of using wilt scores from a systematically-repeated susceptible control in covariate analysis was tested. Covariance analysis significantly improved overall screening by 3% in 1993, but the improvement was non-significant in 1994. The results emphasize the relative uniformity of disease pressure in the wilt-sick plot and suggest that covariance analysis of a systematically arranged control will be of greater benefit in land which is less uniformly infected.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 76
    ISSN: 1573-5060
    Keywords: Microdochium nivale ; resistance ; wheat ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Experiments to assess variation in the resistance of winter wheat to infection by Microdochium nivale were conducted over two consecutive years. Resistance was evaluated using an agar disk technique to reproduce stem lesions and by spraying a conidial suspension to reproduce head blight symptoms. Significant variation for stem reaction measured as stem lesion area (SLA), and head reaction measured as disease severity (DS) was found in the 33 winter wheat genotypes tested. Data obtained over two years in controlled environment conditions were significantly correlated (r=0.713 for SLA and r=0.738 for DS), whereas field data showed a significant genotype x year interaction for disease severity. Quantitative variation for susceptibility to stem and head infection by M. nivale was found among the 33 genotypes tested. The majority of genotypes expressed moderate susceptibility, with cultivar Goupil being very susceptible to both stem and head infection, and the remainder, Renan, Arminda, Munstertaler and Saint-Johann were the most resistant. Resistance to stem and head to M. nivale were not correlated (r=0.358).
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 77
    ISSN: 1573-5060
    Keywords: tomato ; Lycopersicon esculentum ; wild species ; Fusarium oxysporum f.sp. lycopersici ; resistance ; genetic variation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Wild Lycopersicon accessions were screened for resistance to the Fusarium wilt disease caused by Fusarium oxysporum f.sp. lycopersici (Fol) race 1 and race 2. In total, four isolates of each race were used. Among 17 accessions of six Lycopersicon species tested, a wide genetic variation for wilt resistance was observed. Most accessions were highly susceptible, some showed intermediate resistance, but one accession of L. cheesmanii (G1.1615 = PI 266375) and two accessions of L. chilense (G1.1556 and G1.1558) were highly resistant to Fol races 1 and 2. The resistance in the latter three accessions equalled or was higher than the resistance determined by the known I-genes, that have been widely used in breeding programmes. These newly found resistant accessions provide breeders with more opportunities for Fusarium disease resistance and may contribute to our understanding of Fusarium disease resistance gene organisation and evolution.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 78
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 94 (1997), S. 183-189 
    ISSN: 1573-5060
    Keywords: barley ; barley leaf rust ; Puccinia hordei ; scald ; Rhynchosporium secalis ; earliness ; landraces ; leafiness ; plant height ; partial resistance ; resistance ; 1000 grain weight
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Up to 100 single plant derived lines of 18 barley landraces, collected from 18 localities of six barley growing regions of Ethiopia were studied for two years at Holetta, Ethiopia for variation in five quantitative traits; scald severity, earliness, plant height, 1000 grain weight, and leafiness. The relative latent period in the adult plant stage to barley leaf rust, a good measure for partial resistance, was assessed on the landrace lines at Wageningen, The Netherlands. The observed variation between and within landraces was very large for all traits. The magnitude of variation was so large that most, if not all, plants within a landrace had a different genotype. The landraces also varied in the degree of variation. Some landraces, 1726 and 3288 for instance, were more variable for most or all traits than other landraces such as 208925 and 212938. Days to heading and scald severity were significantly (P = 0.01) correlated with altitude, r being 0.66 and - 0.65, respectively. Resistance to scald and leafiness also increased with altitude. On average landraces became later, more resistant to scald and more leafy the higher the altitude of collection. This associated complex of traits could be an adaptation to the wetter and cooler conditions at higher altitudes.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 79
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 185 (1996), S. 173-182 
    ISSN: 1573-5036
    Keywords: arbuscular mycorrhiza ; Fusarium-wilt ; Oidium lini ; plant health ; resistance ; tolerance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Effects of arbuscular mycorrhizal (AM) symbiosis on health ofLinum usitatissimum infected by fungal pathogens were investigated exemplarily. Physiological and biochemical analyses were done to explain the mechanisms underlying the AM effects. AM plants showed increased resistance against the wilt pathogen (Fusarium oxysporum f. sp.lini), the level of this effects depended on the plant cultivars which all showed the same level of root colonization by arbuscular mycorrhizal fungi (AMF). In contrary to that, AM plants were highly susceptible against the shoot pathogenOidium lini, but they suffered less than non-AM plants in terms of shoot fresh weight, CO2 assimilation and content of sucrose in shoot apex. This indicates that AM not only activates resistance mechanisms but also can induce tolerance against pathogens. The concentration of phytohormones such as auxin- and gibberellin-like substances were increased in shoots of AM plants. In roots the ethylene production was increased, too. Furthermore the content and composition of free sterols were highly altered in leaves of AM plants. Root infection by AMF caused an increased respiratory activity and a reduced degree of DNA methylation, but both modifications only occurred in infected root parts indicating an increasing gene activity. The presented results suggest that nearly all parts of a plant are influenced by AM but not in the same manner. In the case of mildewed linseed the effect of AM on plant health was impressing, it indicates that AM has an ability to induce tolerance.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 80
    ISSN: 1573-5060
    Keywords: doubled haploids ; Fusarium oxysporum ; fusarium wilt ; Linum usitatissimum ; resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The inheritance of resistance to fusarium wilt (Fusarium oxysporum f.sp. lini) was investigated in Linum usitatissimum as a first step towards gaining an understanding of the molecular genetics of the disease and developing a procedure for marker-assisted selection. A recombinant doubled haploid (DH) population was derived from the haploid component of polyembryonic F2 seeds originating from a cross between a wilt resistant, twinning Linola™ Linola is a registered trademark of CSIRO line CRZY8/RA91 and the wilt susceptible Australian flax cultivar Glenelg. The segregation of resistance was studied in 143 DH lines under glasshouse and field conditions. Most of the phenotypic variation was attributable to the segregation of two independent genes with additive effects. Minor resistance genes may have also contributed by modifying the resistance response. A glasshouse screening method of DH lines proved a reliable indicator of field resistance to fusarium wilt.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 81
    ISSN: 1573-5060
    Keywords: apple ; fire blight ; resistance ; somaclonal variation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Four somaclonal variants regenerated from adventitious buds of the apple variety Greensleeves were preselected on the basis of their reduced fire blight susceptibility. The present study aimed at assessing precisely their level of fire blight resistance through various inoculation techniques (on in vitro leaves and microcuttings, on greenhouse plants and in field conditions). Overall results of these tests indicated that one clone (R 46/3) was clearly less susceptible than the control. This clone was also characterized as a ‘spur’ variant, with a reduced growth which can explain its limited susceptibility to fire blight. A second clone (R 20/63) was slightly less susceptible than the control in greenhouse and field tests, but this low level of resistance was overcome by high concentrations of inoculum. The absence of variation in chromosome number and isozyme patterns confirmed the genetic trueness-to-type of these four somaclones.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 82
    ISSN: 1573-5060
    Keywords: genetic control ; maize streak virus ; major genes ; minor genes ; resistance ; Zea mays ; maize
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary S1 to S5 inbred lines, derived from a maize population bred for its overall resistance to three tropical viruses, were screened for resistance to maize streak virus (MSV) by artificial plant infection using viruliferous leafhoppers. Symptoms were rated and intra-line frequency distributions studied for all pedigree inbred lines. Mortality due to MSV was very low among these inbreds. Symptoms appeared later, developed slower and were less severe than in the susceptible control hybrid. Results of a study of 500 S1 and 93 S2 lines suggested that resistance is under genetic control via a system involving loci with major genes (with dominance for resistance) controlling high to complete resistance, associated with a genetic system involving loci with minor genes controlling partial resistance. Lines expressing complete resistance to MSV were developed from 5 cycles of inbreeding and selection. The relevance of such complete and partial resistance is discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 83
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat ; Tilletia indica ; Karnal bunt ; resistance ; inheritance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Karnal bunt caused by Tilletia indica in wheat seriously affects the quality of the grains. It is important to generate information on the genetics of resistance to this pathogen so as to aid resistance breeding. For this purpose, four Karnal bunt-resistant lines from China, Brazil and CIMMYT (International Maize and Wheat Improvement Center) and a susceptible Indian cultivar, WL711, were used. The parents, F1 and F3 progenies of five parental diallel crosses revealed that independently segregating loci with three partial dominant resistance alleles were involved in the resistance of Karnal bunt. Lines RC7201/2*BR2 and Roek//Maya/NAC carried one locus for resistance while Shanghai#7 and Aldan/IAS58 have two and three loci, respectively. One common locus was present in all four resistant parents, which imparted a high level of resistance.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 84
    ISSN: 1573-5060
    Keywords: Erysiphe graminis f. sp. secalis ; fitness costs ; powdery mildew ; Secale cereale ; resistance ; rye
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A synthetic winter rye population was produced with two race-specific powdery mildew resistance genes, one dominant (Rm1) and the other (rm2) recessive, each at a frequency of about 0.50. The population was advanced by open-pollination in an isolated plot under mildew-free conditions for eight years. Samples of generations Syn-0 through Syn-7 were inoculated in the laboratory with two mildew isolates, one avirulent to either resistance gene, the other virulent to Rm1 and avirulent to rm2, to discriminate resistant and susceptible phenotypes. From the proportions of resistant plants, frequencies of Rm1 and rm2 were calculated and the fitness of carriers of resistance alleles was estimated in relation to carriers of susceptibility alleles at the two loci using continuous models and linear regression analyses. Frequencies of the two resistance genes oscillated only weakly over the eight generations. Coefficients of selection against Rm1-and rm2rm2 genotypes were −0.04 and −0.02, respectively, and not significantly different from zero. Thus the two resistance genes were selectively neutral. It is concluded that pyramiding of major powdery mildew resistance genes in rye varieties should not reduce their yield potential in the absence of mildew.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 85
    ISSN: 1573-5060
    Keywords: resistance ; yellow rust ; stripe rust ; Puccinia striiformis ; wild emmer wheat ; Triticum dicoccoides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Seedlings of 38 wild emmer derivatives, and a total of 53 advanced wheat varieties/lines introduced from the International Maize and Wheat Improvement Centre (CIMMYT) or other sources, Nepalese breeding lines and local cultivars were inoculated with 18 different yellow rust isolates to postulate yellow rust resistance genes (Yr). Many wild emmer wheat derivatives used were resistant to all isolates indicating the presence of undescribed genes. Some derivatives carried Yr9, Yr6 and/or YrSU. Genes Yr1, Yr2, Yr6, Yr7, Yr8, Yr15, YrSU and YrA+ are no longer effective in Nepal; Yr4, Yr5, Yr9, Yr10, YrSP and YrSD are still effective; the effectiveness of Yr3 remains unclear. This study shows that stripe rust resistance in seedling stage of most Nepalese cultivars and advanced materials is based on Yr9 with combinations of Yr2, Yr6, Yr7, and YrA+, of which only Yr9 is still effective in Nepal. In many countries Yr9 has lost its effectiveness. Therefore the introduction of new Yr-genes from wild emmer wheat in Nepalese cultivars is highly important.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 86
    ISSN: 1573-5060
    Keywords: Zea mays ; insect vectors ; resistance ; maize ; maize streak virus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Settling, probing and oviposition behaviour ofCicadulina mbila, the main vector of maize streak virus (MSV) disease were studied on four maize genotypes, 100MSR, HASR, Reunion and H512. Of the four, only H512 was completely susceptible to MSV while the other three genotypes were all known to have some resistance to MSV. Generally,C. mbila settled in higher numbers on the MSV susceptible genotype compared to the three virus resistant ones. However, the number of probing marks left on H512 and 100MSR were similar while more marks were made on Reunion and HASR in increasing order. The oviposition patterns were similar to those observed for probing behaviour. The results suggest the existence of potentially useful resistance mechanisms against the vector. The possible implications of these results are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 87
    ISSN: 1573-5060
    Keywords: Sorghum bicolor ; Peronosclerospora sorghi ; downy mildew ; inoculation technique ; resistance ; sorghum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Six inoculation techniques were compared for the artificial promotion of downy mildew (Peronosclerospora sorghi) in sorghum. These were (1) sprouted seeds incubated between sporulating infected leaves, (2) sprouted seeds depped in conidial suspension, (3) sprouted seeds sprayed with conidial suspension, (4) seedlings at plumule stage inoculated with drops of a conidial suspension, (5) seedlings at plumule stage sprayed with a conidial suspension, and (6) seedling showered with conidia falling from infected leaves. Seedlings at the one-leaf stage sprayed with a conidial suspension (6 × 105 ml-1) showed the highest systemic infection (100%) in the susceptible lines IS 643 and IS 18433. This technique is effective, repeatable, and allows the deposition of a conidial suspension as a fine mist on the entire seedling surface. In the greenhouse, the technique was used to test the downy mildew reaction of genotypes previously reported as resistant (〈 5% incidence) in 3–4 years of field screenings. Of the 61 genotypes tested, 21 were free from downy mildew, 14 had less than 5% incidence, and the rest showed variable susceptible reactions. Therefore, the technique can be reliably and effectively used in the greenhouse to detect disease escapes and to indentify resistance.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 88
    ISSN: 1573-5060
    Keywords: Cucumis sativus ; gene cluster ; potyvirus ; zucchini yellow mosaic virus ; Moroccan watermelon mosaic virus ; resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Inbred lines derived from the Chinese cucumber (Cucumis sativus L.) cultivar, ‘Taichung Mou Gua’ (TMG), have been shown to be resistant to several potyviruses including: zucchini yellow mosaic virus (ZYMV), zucchini yellow fleck virus (ZYFV), watermelon mosaic virus (WMV) and the watermelon strain of papaya ringspot virus (PRSV-W). Recently, an additional virus that infects cucurbits, the Moroccan watermelon mosaic virus (MWMV), has been determined to be a distinct member of the potyvirus group. This study demonstrates that TMG-1 possesses resistance to MWMV. Rub or aphid inoculated TMG-1 seedlings remain free of symptoms. Progeny analyses of the F1, F2 and backcross generations show that resistance to MWMV is conferred by a single recessive gene (proposed designation, mwm). Sequential inoculation of progeny possessing resistance to ZYMV followed by MWMV (or MWMV followed by ZYMV) and analysis of F3 families derived from F2 individuals selected for resistance to ZYMV indicate that both resistances are conferred by the same gene, or two tightly linked genes.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 89
    ISSN: 1573-5060
    Keywords: banana ; Musa spp. ; Mycosphaerella fijiensis ; black leaf streak ; resistance ; selection ; toxin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The results of our experiments suggest that toxin(s) of Mycosphaerella fijiensis would be involved neither in infection initiation, nor in the hypersensitive reaction in highly resistant cultivars but could serve at most as secondary determinant of the pathogenicity, contributing to the lesion expansion in cultivars exhibiting partial resistance to Black Leaf Streak disease. Moreover, the effects of toxin(s) on chlorophyll fluorescence, as well as preliminary electron microscopy observation, suggest that chloroplasts could be a precocious site of action of the toxin(s). Therefore, in vitro heterotrophic tissues would not be a suitable target to perform the screening with such toxin(s). The prospects and limitations of M. fijiensis toxin(s) for screening banana for resistance to Black Sigatoka are highlighted.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 90
    ISSN: 1573-5060
    Keywords: Avena sativa ; powdery mildew ; resistance ; oat cultivars
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Common oat (Avena sativa L.) cultivars and breeding lines grown in Western Europe and North America were tested against twelve Erysiphe graminis f. sp. avenae mildew isolates collected in Germany and Denmark. These isolates were selected for their ability to produce differential response patterns permitting characterization of five oat mildew resistance (OMR) groups. From a total of 259 cultivars and lines tested 173 accessions showed susceptible responses, 48 accessions were characterized by susceptible or intermediate responses and 38 accessions revealed isolate-specific resistance response patterns. Eight cultivars and lines had resistance patterns of OMR group 1, six cultivars of OMR group 2, and eleven cultivars of OMR group 3. Two cultivars, each possessed resistance patterns corresponding to OMR groups 1 + 3 and 2 + 3 in combination, respectively. Three cultivars exhibited the response pattern of OMR group 3 in association with an additional unknown resistance. Eight cultivars and lines showed a resistance response pattern not yet detected in the documented OMR groups.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 91
    ISSN: 1573-5060
    Keywords: Fragaria spp. ; Phytophthora fragariae var. fragariae ; red core ; red stele ; resistance ; root rot ; strawberry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Race specific resistance to red core (red stele) root rot, caused by Phytophthora fragariae var. fragariae, is known to occur in the cultivated strawberry (Fragaria × ananassa Duch.), but frequently this resistance does not completely prevent infection. We therefore developed a classification method which distinguishes partial and complete resistance. It accounts for differences in the aggressiveness of isolates and in the appropriateness of experimental conditions for infection. This method is based on the microscopically assessed disease severity of a tested strawberry genotype relative to that of an universally susceptible reference cultivar. If the tested genotype is significantly (P≤0.01) less diseased, it is considered to possess resistance. Data from 18 genotype-isolate combinations, including five genotypes (‘Blakemore’, ‘Md683’, ‘Redgauntlet’, ‘Del Norte’, ‘Yaquina A’) and four North American isolates (A2, A4, A6 and A10) demonstrated the validity of our classification scheme.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 92
    ISSN: 1573-5060
    Keywords: Hordeum vulgare s.l. ; barley ; soil-borne yellow mosaic inducing viruses (BaMMV, BaYMV, BaYMV-2) ; resistance ; germplasm ; genetic analysis ; molecular techniques (RFLP, RAPD)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Soil-borne mosaic inducing viruses, i.e., barley mild mosaic virus (BaMMV), barley yellow mosaic virus (BaYMV), and BaYMV-2, cause one of the most important diseases of winter barley in Western Europe. Since resistance of all commercial European barley cultivars is due to a single recessive gene (ym4) which is not effective against BaYMV-2, exotic barley germplasms (Hordeum vulgare L., H. spontaneum Koch) were screened for resistance to the different viruses and analyzed for genetic diversity concerning BaMMV resistance. In these studies it turned out that resistance to BaMMV is entirely inherited recessively and that a high degree of genetic diversity concerning resistance is present within the barley gene pool at least to BaMMV. Therefore, exotic barley germplasms are a very useful source for the incorporation of different resistance genes into barley breeding lines, thereby enabling the breeder to create cultivars adapted to cultivation in the growing area of fields infested by soil-borne viruses. Furthermore, in order to obtain more information on these germplasms they were evaluated for agronomic traits and isozyme, RFLP and RAPD analyses were carried out on these varieties to detect markers linked to the respective resistance genes and to obtain information on the genetic similarity between yellow mosaic resistant barley accessions derived from different parts of the world. Actual results of these studies are briefly reviewed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 93
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 92 (1995), S. 295-300 
    ISSN: 1573-5060
    Keywords: barley ; scald ; Rhynchosporium secalis ; resistance ; Hordeum vulgare
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Twenty Finnish isolates of Rhynchosporium secalis (Oud.) J.J. Davis, the causal agent of scald, were taken from infected barley (Hordeum vulgare L.) plants and inoculated on to seedlings of a differential series of barley containing a range of major genes for resistance to the fungus, as well as on to six Nordic 6-row spring barleys and three winter ryes (Secale cereale L.). These fungal isolates derived from four sites and three host varieties. Disease development was monitored on two leaves of seedlings in the greenhouse employing a standard scale, and on adult plants in the field by assessing the diseased area on the three uppermost leaves. A comparison was also made between the pathogenicity and virulence of ten Finnish and ten Canadian R. secalis isolates. The Finnish isolates varied in virulence, but with the exception of Algerian (CI 1179) seedlings and adult La Mesita (CI 7565) all seedlings and adult plants of the entire differential series were resistant to all isolates. Canadian isolates were, on average, less virulent than Finnish isolates. All the Nordic checks were susceptible to all Finnish and seven Canadian isolates, but differences in the degree of susceptibility were evident. Isolates of R. secalis from barley were non-pathogenic on rye, isolates from Elymus repens L. were non-pathogenic on barley and rye, and isolates from rye were only pathogenic on rye. Finnish R. secalis isolates contain no redundant pathogenic diversity. The differential series represents a useful, but as yet untapped, source of resistance to R. secalis for Finnish barley breeders.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 94
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 92 (1995), S. 375-381 
    ISSN: 1573-5060
    Keywords: dry matter ; lignin ; phenols ; Radopholus similis ; resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The burrowing nematode (Radopholus similis) is one of the major nematode species attacking banana and plantains. Sources of resistance to this nematode were found and studies were made of the resistance mechanisms involved. Relatively greater numbers of preformed phenolic cells were found in roots of the resistant and intermediately resistant cultivars Yangambi km5 and Gros Michel than others. However, in another resistant cultivar, Pisang Jari Buaya, fewer phenolic cells were found, but this clone had high numbers of cells with lignified walls suggesting a different mechanism of resistance. An interesting correlation was found between level of susceptibility to R. similis and root dry matter. A possible role of lignin in resistance to R. similis in Musa is also indicated.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 95
    ISSN: 1573-5060
    Keywords: barley ; Hordeum vulgare ; net blotch ; Drechslera teres ; Pyrenophora teres ; virulence ; resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Six Swedish and one Canadian single spore isolate of Drechslera teres f. teres were used to screen 109 barley lines for disease resistance and to select a differential set of barley lines for use in assessing pathogen virulence. A large variation for net blotch resistance was found among the 109 barley lines which were classified into four groups, those showing: 1) only resistant reactions; 2) differential reactions; 3) only intermediate reactions and 4) only susceptible reactions. The European commercial varieties included, showed susceptibility to all Swedish isolates, but a few were resistant to the Canadian isolate. The 18- member differential set separated 25 Swedish and two Canadian isolates of D. teres into 14 pathotypes, three of which made up 59% of the isolates. Only one barley differential (CI 9776) was resistant to all net form isolates. Host selection on the pathogen seems to be present as all six isolates obtained from cv. Golf belonged to the same pathotype and 4 of 5 isolates from cv. Karin shared the same virulence pattern. The net form of net blotch (D. teres f. teres) predominated in the sampled regions and only one of 26 Swedish isolates was of the spot form (D. teres f. maculata).
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 96
    Electronic Resource
    Electronic Resource
    Springer
    Molecular breeding 2 (1996), S. 297-305 
    ISSN: 1572-9788
    Keywords: transgenic plants ; resistance ; phytopathogenic bacteria ; plant breeding ; genetic engineering ; potato ; tobacco
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 97
    ISSN: 1573-8469
    Keywords: Fusarium head blight ; mycotoxins ; plant breeding ; resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Heads of 12 spring barley genotypes (eight cultivars, four lines) were inoculated with conidial suspensions of twoFusarium culmorum isolates (I1 and I2). Both isolates caused the following significant reductions (%) when compared with the control: number of kernels head−1 12 and 16, weight of 1000 kernels 47 and 24, yield 49 and 37, for I1 and I2 respectively. Both isolates were able to produce average levels (mg kg−1) of deoxynivalenol of 67.1 and 13.9, 3-acetyldeoxynivalenol of 9.4 and 1.4 and zearalenone of 0.3 and 0.4 for I1 and I2 respectively. In kernels of three genotypes inoculated with the same isolates, 15-acetyldeoxynivalenol at an average level (mg kg−1) of 1.3 and 1.5 was detected, while in kernels of six genotypes inoculated with I2, 0.2 of nivalenol was found. A significant correlation for yield and toxin level was found for less pathogenicF. culmorum isolate I2.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 98
    Electronic Resource
    Electronic Resource
    Springer
    European journal of plant pathology 102 (1996), S. 875-881 
    ISSN: 1573-8469
    Keywords: hybrid ; Melampsora ; plant-pathogen interactions ; resistance ; Salix
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Pure species and F1 hybrid families ofSalix viminalis andS. dasyclados were tested for resistance to four single uredinium isolates ofMelampsora rust in laboratory experiments using excised leaves. Rust isolates were derived from:S. viminalis, S. dasyclados, aS. viminalis x triandra hybrid, andS. daphnoides. Incidence of infection, number of uredinia per leaf, and numbers of spores per uredinium were measured. As expected, the isolate fromS. daphnoides did not infect any of the willow species or hybrids tested. For the other three rust isolates that were tested, the parent from which the isolate was derived was susceptible, the other parent was resistant, and hybrids were intermediate in resistance for incidence and uredinia per leaf. These patterns indicate additive inheritance of these resistance traits in hybrids. Numbers of spores per uredinium were similar on the hybrids and the susceptible parent for one rust isolate, suggesting dominant inheritance of this trait in the hybrids.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 99
    ISSN: 1573-8469
    Keywords: dichlofluanid ; fungicides ; genetics ; resistance ; grey mould
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Field isolates ofBotryotinia fuckeliana were collected from naturally infected plants. Their responses to the multisite fungicide dichlofluanid in mycelium growth test fell into three phenotypic classes, characterized by the following EC50 (and MIC) values inμg ml−1: sensitivity, 1–3 (6–10); low resistance, 3–10 (〉 100); high resistance, 10–30 (〉 100). The corresponding values obtained for these classes in a spore germination test were respectively: ≅ 0.05 (0.2), 0.05–0.1 (0.5), 0.5–1 (0.9–1.5). Resistant isolates were crossed with two sensitive and two resistant strains of appropriate mating type to determine the genetic basis of resistance. Distribution of resistance phenotypes in ascospore progeny indicated that a gene, namedDic1, was probably responsible for the low or high resistance of 14 mutants selectively collected from experimental plots of greenhouse-grown gerbera sprayed several times with dichlofluanid or tolyfluanid. A second gene, namedDic2, was probably responsible for the low resistance displayed by two isolates (from grapevine and from carnation) maintained in the laboratory collection. As a result of the investigation, the use of dichlofluanid in integrated management programmes against grey mould is discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 100
    ISSN: 1573-8469
    Keywords: Fusarium head blight ; mycotoxins ; plant breeding ; resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Twelve barley genotypes were inoculated with two F. graminearum isolates of different chemotype I1 #148 (producing nivalenol/deoxynivalenol) and I2 #108 (deoxynivalenol/acetyldeoxynivalenol). For both I1 and I2 isolates, respectively, reductions (%) in number of kernels head-1 10.6 and 14.3; yield 39.6 and 35.7; weight of 1000 kernels 36.9 and 23.2 were observed in inoculated plants from control values. Chemical analysis revealed the presence (average concentration mg kg-1) of deoxynivalenol (1.3) and nivalenol (3.2) in kernels of all genotypes inoculated with the I1 isolate, and zearalenone (0.2) in three samples. After inoculation with the I2 isolate, deoxynivalenol (37.8) and zearalenone (0.4) were found in kernels of all genotypes, while 3-acetyldeoxynivalenol and 15-acetyldeoxynivalenol, respectively, were determined in five and four samples only. No significant correlation between examined characteristics was found for either the I1 or I2 isolate. The results obtained contribute information on the accumulation of toxins in cereal grain inoculated with F. graminearum isolates of different chemotypes.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...