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  • wheat  (36)
  • Springer  (36)
  • Elsevier
  • 2015-2019
  • 2010-2014
  • 1985-1989  (36)
  • 1989  (36)
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Publisher
  • Springer  (36)
  • Elsevier
Years
  • 2015-2019
  • 2010-2014
  • 1985-1989  (36)
Year
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Entomologia experimentalis et applicata 53 (1989), S. 17-29 
    ISSN: 1570-7458
    Keywords: Mayetiola destructor ; Cecidomyiidae ; oviposition ; host specificity ; wheat ; oats ; insect-plant interactions ; thresholds ; deprivation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les réactions de femelles préalablement accouplées de Mouches de Hesse ont été examinées en analysant le comportement de femelles isolées sur blé et sur avoine. Le répertoire comportemental de ces femelles comprenait: le vol, l'atterrissage sur feuille, la flexion du corps de sorte que l'extrémité de l'abdomen touchât la surface de la feuille, l'antennation, les mouvements de l'extrémité de l'abdomen sur la feuille à angle droit des nervures, le repos avec la tarière droite et encore dévaginée, le repos avec la tarière télescopée à l'intérieur du corps. Sur blé plus que sur avoine, les femelles après atterrissage ont présenté une fréquence plus élevée de passage de la flexion à l'antennation que de la flexion à l'abdomen droit. Durant les 5 premières minutes d'observation, les individus libérés dans des enceintes avec blé fléchirent et ‘antennèrent’ 2 à 3 fois plus que ceux libérés sur avoine. Les durées des différentes séquences différaient aussi: sur blé, pendant les 5 premières minutes, les femelles passèrent plus de 50% du temps à fléchir, tandis que sur avoine elles passèrent plus de 50% du temps en repos. Les femelles restèrent aussi plus longtemps sur les feuilles de blé et y pondirent 4 fois plus d'oeufs que sur avoine. Les femelles de M. destructor ont montré une plasticité du seuil d'acceptation. Pendant les premières heures de ponte, elles ont été très sélectives et refusèrent, ou ne pondirent que quelques oeufs sur avoine, mais acceptèrent volontiers le blé. La discrimination s'est poursuivie tant que les femelles ont eu accès au blé en même temps qu'à l'avoine. Cependant, quand les femelles ont été privées de blé pendant plusieures heures, l'acceptation de l'avoine a augmenté. Cet accroissement de l'acceptation a eu lieu à peu près au moment où les femelles sur blé pondaient leurs derniers oeufs.
    Notes: Abstract Responses of mated female Hessian flies were investigated by analysing the behaviour of individual flies in wheat and oats. The behavioural repertoire of such females included: flying, alighting on leaves, arching of the body so that the tip of the abdomen touched the leaf surface, antennation, movements of the tip of the abdomen across the leaf at right angles to leaf veins, sitting with the ovipositor straight but still extended, and sitting with the ovipositor telescoped into the body. After alighting, females on wheat showed a higher frequency of transitions from arching to antennation and a lower frequency of transitions from arching to abdomen straight than females on oats. During the first 5 min of observations, individuals released into arenas with wheat arched and antennated 2–3 times more frequently than females released into oats. Time allotted to behaviours also differed; during the first 5 min, females in wheat spent 50 percent more time arching, whereas females in oats spent 50 percent more time sitting. Females in wheat also stayed longer and laid 4 times more eggs than females in oats. Temporal changes in egglaying were monitored by quantifying hourly rates of egglaying in no-choice assays for several hours following mating at 9:00 am. During the first and second hours post-mating, egglaying occurred infrequently. However, during the third hour post-mating (11:00 am to noon) females on wheat laid 5 times more eggs than females on oats. Rates of egglaying decreased on wheat but increased on oats during the fourth hour, and then during the fifth hour, decreased on both wheat and oats. Changes in egglaying responses were also evident when behaviours of individual females were measured 1–3 h vs. 3–7 h post-mating. Females deprived of host plants and released into wheat or oats later in the day showed higher frequencies of arching and antennation and laid more eggs before leaving the arena.
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  • 2
    ISSN: 1570-7458
    Keywords: Coccinella septempunctata ; Coccinellidae ; wheat ; egg laying ; larva ; adult ; vertical distribution ; Coccinella septempunctata ; Coccinellidae ; blé ; ponte ; larve ; adulte ; répartition spatiale
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Summary At the beginning of spring, post-hibernating adults of Coccinella septempunctata L. (Col., Coccinellidae), larvae and nymphs are found on the lower part of wheat plants. In June, adults born in the field as well as their progeny are dispersed all over the plant and a significant proportion of them is found on the apical parts of plants. Most of the egg clutches are layed on soil lumps, stones and small wild plants which represent preferential sites. Variations in coccinellid distribution may be influenced by climatic conditions, especially the temperature, by the thermophilic nature of this species and by the repartition of the three main aphid species on the plants. These results are relevant for the selection of a sampling methods.
    Notes: Résumé Au début du printemps les adultes de Coccinella septempunctata L. (Col., Coccinellidae) issus des sites d'hivernation, les larves et les nymphes qui en proviennent, fréquentent le sol et les parties basses du blé. En juin, les adultes nés dans le champ et leur descendance sont dispersés sur toute la hauteur des talles bien qu'une fraction non négligeable de leur population se rencontre à l'extrémité supérieure. La plupart des pontes sont déposées sous les mottes de terre, les pierres et les petites adventices qui constituent des sites privilégiés. Ces variations de la distribution de cette coccinelle peuvent être mises en relation avec le climat, en particulier la température, avec la thermophilie de cette espèce et avec la répartition sur les différentes parties des talles des 3 espèces de puceron qui se succèdent au cours de la saison. Ces observations sont importantes à considérer lors du choix ou de la mise au point d'une méthode d'échantillonnage.
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  • 3
    ISSN: 1573-0867
    Keywords: Phosphorus ; lupin ; chickpea ; wheat ; nodulation ; dry matter production
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A glasshouse experiment was conducted to examine the comparative growth and P uptake response following P fertilizer application in lupins (Lupinus angustifolius L. cv. Chittick) and chickpeas (Cicer arietinum cv. Tyson) compared to wheat (Triticum aestivum cv. Sunstar). Measurements of dry matter, phosphorus uptake and nodule numbers were made at 50 and 100 days after sowing. At the 50 day harvest, the two legume crops produced less dry matter and accumulated less plant P than wheat but no such species interactions were present at the 100 day harvest. Chickpeas showed strong positive responses in nodule numbers with increasing rates of P fertilizer while such effects were less and more variable with lupins.
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  • 4
    Electronic Resource
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    Springer
    Nutrient cycling in agroecosystems 20 (1989), S. 27-32 
    ISSN: 1573-0867
    Keywords: Cropping system ; phosphorus ; rice ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A long term field experiment was conducted on a sandy loam soil from 1983 to 1987 to determine how to best apply phosphorus fertilizer in a rice-wheat cropping system. The treatments included 9 combinations of phosphorus application either to both rice and wheat or to rice or wheat alone. Direct application of phosphorus at 13 kg/ha to both the crops resulted in significantly higher total productivity of the rice-wheat cropping system as compared with 26 kg P/ha applied either to rice or wheat alone. Phosphorus at 13 kg/ha for rice and 26 kg/ha for wheat was as efficient as 13 kg P/ha for rice and 13 kg P/ha for wheat. The higher rate of P (26 kg/ha) applied to both rice and wheat resulted a decline in the total productivity. The residual effects of phosphorus applied to either rice or wheat were significant to the succeeding crop but was inferior to its direct application. Phosphorus increased the leaf area index, chlorophyll content of leaves, and interception of more photosynthetically active radiation (PAR) which resulted in increased grain yield of rice and wheat. Phosphorus status of the surface soil declined markedly, in the absence of P application from 15.4 to 6.4 kg P/ha. Phosphorus applied at 26 kg P/ha to both the crops resulted a build up of the available P status of soil. Phosphorus application at 13 kg/ha to both rice and wheat maintained the phosphorus status of the soil at original level.
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  • 5
    Electronic Resource
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    Springer
    Nutrient cycling in agroecosystems 20 (1989), S. 59-66 
    ISSN: 1573-0867
    Keywords: Ammonia volatilization ; nitrogen leaching ; denitrification ; time of N application ; wheat ; Triticum aestivum ; Triticale ; irrigation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Grain yield, nitrogen (N) assimilation, ammonia (NH3) volatilization, denitrification and fertilizer N distribution were examined in three commercially grown cereal crops; two were sown into conventionally tilled fields, while the third was direct drilled into an untilled field. The crops were top dressed with urea at establishment, tillering or ear initiation. Crop yield and N assimilation were measured in 16 m by 2.5 m plots receiving 0, 35, 70, 105, 140 or 175 kg N ha−1. A mass balance micrometeorological technique was used to measure NH3 volatilization, and other fertilizer N transformations and transfers were studied using15N labelled urea in microplots. On the conventionally tilled sites application of urea increased the grain yield of wheat from 3.9 to 5.5 t ha−1, when averaged over the five application rates, three application times and two sites. There were no site or application time effects. However, on the direct drilled site, time of application had a significant effect on grain yield. When urea was applied at establishment, grain yield was not significantly increased and the mean yield (2.81 t ha−1) was less than that obtained from treatments fertilized at tillering or ear initiation (4.09 and 4.0 t ha−1, respectively). Much of the variation in grain yield at the no-till site could be ascribed to differences in NH3 volatilization. At the no-till site, NH3 losses were equivalent to 24, 12 and 1% of the N applied at establishment, tillering and ear initiation, respectively. Negligible volatilization of NH3 occurred at the other sites. The surface soil at the no-till site had the highest urease activity and the soil was covered with alkaline ash resulting from stubble burning. Plant recovery of fertilizer N did not vary with application time on conventionally tilled sites (mean 62%). However, plant recovery of15N applied to the no-till site at establishment (35% of the applied N) was significantly less than that from plots where the application was delayed (45% at tillering and 55% at ear initiation, respectively). Leaching of N to below 300 mm depth was minimal (0 to 5% of the applied N). The calculated denitrification losses ranged from 1% to 14% of the applied N. The results show that the relative importance of NH3 volatilization, leaching and denitrification varied with site and fertilization time. The importance of the various N loss mechanisms needs to be taken into account when N fertilization strategies are being developed.
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  • 6
    ISSN: 1573-5028
    Keywords: chloroplast DNA ; cytochrome b-559 ; photosystem II ; psbL ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The N-terminal amino acid sequence of a 3.2 kDa photosystem II polypeptide is shown to be identical to that of a polypeptide encoded by an open reading frame of 38 codons (orf38) in wheat chloroplast DNA. Orf38 is located just downstream of the psbE and psbF genes for the polypeptides of cytochrome b-559. Analysis of the transcription of this region of chloroplast DNA shows that psbE, psbF and orf38 are co-transcribed to give a 1.1 kb polycistronic transcript which also contains another open reading frame of 40 codons. The orf38 and orf40 products are hydrophobic polypeptides which are both predicted to span the thylakoid membrane once. Orf38 and orf40 are highly conserved, and map to similar locations adjacent to psbE and psbF, in all organisms from which this region of DNA has been sequenced. We propose that orf38 is named psbL.
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  • 7
    ISSN: 1573-5028
    Keywords: ADP-glucose pyrophosphorylase ; cDNAs ; gene organisation ; polypeptides ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A cDNA clone (WL : AGA.1) encoding wheat leaf ADP-glucose pyrophosphorylase has been isolated from a λgt11 expression library, by immunological screening with anti-spinach leaf ADP-glucose pyrophosphorylase serum. The WL : AGA.1 cDNA is 948 bp long and contains approximately 55% of the complete wheat leaf ADP-glucose pyrophosphorylase mRNA sequence, estimated from Northern blot experiments. A wheat endosperm cDNA library was subsequently constructed in λgt11 and six clones hybridising to the cDNA insert of clone WL : AGA.1 were isolated. The longest of these wheat endosperm ADP-glucose pyrophosphorylase cDNAs, clone WE : AGA.7, is nearly full-length (1798 bp), indicated by Northern blot analysis of wheat endosperm mRNA and nucleotide sequence analysis. Southern hybridisation analysis and restriction enzyme mapping indicated that the wheat leaf and wheat endosperm ADP-glucose pyrophosphorylase cDNAs and genes are members of two distinct gene families. In addition, restriction enzyme mapping revealed polymorphism in the wheat endosperm ADP-glucose pyrophosphorylase cDNAs, indicating the existence of at least two wheat endosperm ADP-glucose pyrophosphorylase gene sub-families. Subsequent nucleotide sequence analysis indicates that there is approximately 55% identity between wheat leaf and wheat endosperm ADP-glucose pyrophosphorylase cDNAs. In contrast, members of each sub-family of endosperm cDNA, represented by clones WE : AGA.3 and WE : AGA.7, are 96% identical.
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  • 8
    ISSN: 1573-5028
    Keywords: aleurone ; barley ; protoplasts ; transient expression ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Methods have been developed for the isolation of aleurone protoplasts from developing caryopses of Hordeum vulgare and Triticum aestivum in order to study transient expression of introduced genes. Chimaeric gene constructs were introduced into aleurone protoplasts by polyethylene glycol (PEG). Transient expression directed by the 35S promoter from cauliflower mosaic virus (CaMV) of the reporter gene encoding chloramphenicol acetyl transferase (CAT) was detected in aleurone protoplasts from developing barley and wheat grains. Using a similar construct, CAT activity increased when the alcohol dehydrogenase intron 1 fragment from maize was ligated between the 35S promoter and the CAT coding region. The demonstration of transient expression in protoplasts from developing aleurone layers indicates that they may be useful for investigating tissue and developmental control of genes coding for cereal seed proteins.
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  • 9
    ISSN: 1573-5028
    Keywords: F1F0 ATPase ; chloroplast coupling factor ; mitochondrial gene ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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  • 10
    Electronic Resource
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    Plant and soil 120 (1989), S. 125-131 
    ISSN: 1573-5036
    Keywords: canola ; fallow ; N mineralization ; N immobilization ; organic matter ; rhizosphere ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A greenhouse experiment was conducted to determine the influence of cropping variables on nitrogen dynamics in a soil amended with green manure. Surface soil from various long-term spring wheat rotations was amended with15N-labelled legume green manure (Lathyrus tingitanus) and subsequently cropped (canola [Brassica napus] and spring wheat [Triticum aestivum]) or incubated without a crop for 56 days in a greenhouse. Nitrogen mineralization from both the indigenous soil N and from green manure was suppressed in cropped soil. Net N mineralization in the uncropped and cropped treatments averaged 73 and 43 mg kg−1, respectively. This difference was attributed, in part, to enhanced biological immobilization in the rhizosphere. Previous cropping practices also had significant effect on N mineralization, largely by their influence on indigenous organic matter quality. These observations suggest that short-term N mineralization is favored by fallowing soil after green manure application whereas N retention in organic matter is favored by immediate cropping.
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  • 11
    ISSN: 1573-5036
    Keywords: characterization ; deleterious rhizobacteria ; inhibitory bacteria ; pseudomonads ; toxin ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A toxin produced by a deleterious rhizobacterial pseudomonad that inhibits both winter wheat (Triticum aestivum L.) root andEscherichia coli growth was characterized. The toxin was rapidly deactivated at pH 2 and 12 and by autoclaving (121°C, 15 minutes). Less toxin was destroyed as the temperature and time of exposure decreased, and at 40°C it was stable for at least 24 hours. The toxin was extremely polar and could not be extracted from culture filtrates with organic solvents. The compound eluted after the void volume from a Sephadex G-10 column indicating a molecular weight of less than 700. The toxin adsorbed to Dowex 50W strong cation exchange resin and eluted with 2M NH4OH. Numerous thin layer chromatography solvent systems were unsuccessful at purifying the toxin. The partially purified toxin inhibited several different microorganisms while the producing strains were resistant. The toxin appears unique to toxins produced by recognized plant pathogenic bacteria.
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  • 12
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    Euphytica 42 (1989), S. 41-44 
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat ; frost resistance ; locus Fr1 ; recombinant lines ; chromosome 5A
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary A gene for frost resistance on chromosome 5A of wheat was located using single chromosome recombinant lines from the cross between the substitution line Hobbit (Triticum spelta 5A) and Hobbit. In this sample of recombinant lines the locus for frost resistance, designated Fr1, is completely linked to the locus Vrn1 controlling vernalisation requirement. The results can be explained by a pleiotropic action of the Vrn1 locus or close genetic linkage between Vrn1 and Fr1. Further detailed study is necessary to resolve these alternative hypotheses.
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  • 13
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat ; dwarfing genes ; drought stress ; yield ; yield components
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Near-isogenic tall (no dwarfing gene), semidwarf (Rht1 or Rht2) and dwarf (Rht1 + Rht2 or Rht3) spring wheat lines were evaluated for yield and yield components under irrigated and rainfed conditions. Under irrigated conditions, the dwarf and the semidwarf lines exhibited a significant yield advantage over the tall lines. Under rainfed conditions, the semidwarf lines outyielded the tall as well as the dwarf lines. Percent yield reduction in response to drought stress was highest with the dwarfs and lowest with the tall lines. Dry matter production of the tall lines and that of the semidwarf lines did not differ significantly and both produced significantly more dry matter than the dwarf lines under irrigated as well as rainfed conditions. Plant height and kernel weight decreased with increasing degree of dwarfness while number of kernels per spikelet, harvest index and days to heading increased under both moisture regimes. The dwarfing genes did not have any significant influence on number of tillers/m2 and spikelets per spike in either moisture regime.
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  • 14
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat ; chromosome substitution ; frost resistance ; hardening
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The highly frost resistant wheat variety Cheyenne (donor) and the poorly frost resistant variety Chinese Spring (recipient) were frozen at −9° C and −11° C at various stages of hardening, as were a number of substitution lines of these two varieties (CS/Ch 3A, CS/Ch 5A, CS/Ch 7A, CS/Ch 2B, CS/Ch 4B, CS/Ch 5B, CS/Ch 4D, CS/Ch 5D). Chromosomes 5A, 5B, 5D, 4B and 7A of Cheyenne increased the frost resistance of the recipient variety to varying extents. However, the frost resistance changed not only as a function of the different chromosomes, but also as a function of the duration of hardening, indicating that genes responsible for frost resistance are expressed differently during different phases of the hardening process.
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  • 15
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat ; Puccinia recondita ; leaf rust resistance ; alien gene transfers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Nine transfers of leaf rust (Puccinia recondita Rob. ex Desm.) resistance to wheat (Triticum aestivum L.) from Agropyron elongatum Host. Beauv., Triticum speltoides Tausch and rye (Secale cereale L.) were backcrossed up to 10 times to commercial wheat cultivars. The objective was to study the effect of the transfers on agronomic and quality characters and to make them available in desirable genetic backgrounds. The results varied greatly for different transfers. In four cases no promising material was obtained even after nine backcrosses. However, for the remaining five transfers material with potential as a new cultivar was obtained.
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  • 16
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat ; Puccinia recondita f. sp. tritici ; wheat leaf rust ; partial resistance ; latency period ; gene action ; oligogenic inheritance ; transgressive segregation ; number of genes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Crosses were made between the highly susceptible Little Club and the partially resistant cultivars Westphal 12A, Akabozu and BH 1146 to obtain F1, F2 and backcross generations. Latency period (LP) was determined in plants inoculated at the young flag leaf stage with a monospore culture of race ‘Flamingo’ of wheat leaf rust. Broad sense heritability of LP in the F2 averaged 0.8. The genes showed partial to almost complete recessive inheritance. Scaling tests indicated that additive gene action was the most important factor in the inheritance of partial resistance. The tests showed that there were no indications for additive x additive, additive x dominance or dominance x dominance interactions. The number of effective factors was estimated as one or two for Akabozu, three or more for Westphal 12A, and two or three for BH 1146. BH 1146 also possessed a (semi-)dominant gene for a lower infection type which was temperature sensitive in its expression. The genes of the various parents had unequal effect on LP.
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  • 17
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat ; Puccinia recondita f. sp. tritici ; wheat leaf rust ; partial resistance ; latency period ; oligogenic inheritance ; transgressive segregation ; number of genes ; heritability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Three partially resistant spring wheat cultivars, with a long latency period were crossed among each other and with the highly susceptible Little Club, with a very short latency period. Parents, F3 and F5 plants have been inoculated with the leaf rust race Flamingo in the young flag leaf stage to determine the latency period. From the crosses with Little Club, it was concluded that Westphal 12A carries three, Akabozu two and BH 1146 two or three genes for a longer latency period. BH 1146 appears to carry also one hypersensitive resistance gene. Transgressive segregation occurred in crosses between partially resistant cultivars. From crosses between the partially resistant cultivars, it was concluded that the genes in Akabozu and Westphal 12A are different, while those in Akabozu and BH 1146 are at least partly different. The possibilities of accumulation of LP-prolonging genes are discussed.
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  • 18
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat ; anther culture ; callus initiation ; cytoplasm ; cytoplasmic male sterility
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Nuclear and cytoplasmic factors affect tissue culture response in wheat (Triticum aestivum), and cytoplasmic male sterility may enhance callus initiation in anther culture. Three wheat nuclear genotypes, each in normal and two alien cytoplasms conferring cytoplasmic male sterility, were evaluated for callus initiation frequency in anther culture. Nuclear genotype had the greatest effect on callus initiation, but cytoplasm and nucleus X cytoplasm interaction also produced significant effects. The nuclear genotype of ‘Chris’ outperformed ‘Butte’ and ‘Coteau’ in all cytoplasms. Ordinary wheat and Triticum timopheevi cytoplasms outperformed Aegilops speltoides cytoplasm. Cytoplasmic male sterility did not increase callus initiation. This suggests manipulating the nuclear genotype is the best strategy for improving the capacity of wheat to initiate callus in anther culture.
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  • 19
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    Plant and soil 120 (1989), S. 273-282 
    ISSN: 1573-5036
    Keywords: aluminum toxicity ; biological tests ; calcium deficiency ; root growth ; sorghum ; subsurface soils ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Two relatively simple procedures based on 4-day seedling growth were developed for identifying soil calcium (Ca) deficiency and/or aluminum (Al) toxicity. Test A uses any large-seeded cultivar that a farmer might consider planting and reveals whether the cultivar will suffer from Ca deficiency by comparing root growth in untreated soil to that in soil receiving a minimal Ca addition (0.1 meq.100mL−1 soil), sufficient to eliminate possible deficiency. Al toxicity is detected by comparing root growth in a sample receiving the minimal Ca treatment with growth in the soil treated with enough lime to neutralize exchangeable Al. In test B, potential Al toxicity problems are detected for any widely-grown standard crop by comparing its growth with that of a different, Al-tolerant variety on soil samples receiving 0.1 meq.100mL−1 Ca. With this test Ca deficiency in the untreated sample is detected by an increase in root growth of the Al-tolerant variety resulting from a small addition of Ca. The tests agreed with diagnoses made by standard chemical methods in about 84% of the cases examined. The proposed tests can be carried out using simple, easily-available materials without the necessity of sending soils to an analytical laboratory.
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  • 20
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    Euphytica 40 (1989), S. 103-109 
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat ; triticale ; wheat-triticale hybrids ; Secale cereale ; rye ; Gaeumannomyces graminis ; take-all ; resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Fifteen triticale and wheat-triticale hybrid lines were evaluated for resistance to the take-all fungus Gaeumannomyces graminis var. tritici and compared with five wheat and two rye lines in inoculated field and pot trials. The triticale and wheat-triticale hybrid lines varied in rye chromosome number and degree of resistance expressed. One line, Venus with seven pairs of rye chromosomes consistently showed levels of resistance intermediate between wheat and rye. A trend was observed where increasing rye chromosome content led to greater resistance but exceptions showed that variation within triticales could not be ascribed to rye chromosome content alone.
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  • 21
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat ; gliadins ; electrophoresis ; cultivar identification ; breeding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The process of the separation of gliadin proteins of wheat, using polyacrylamide gel electrophoresis, was studied in detail. It was shown that electrophoresis is a dynamic process during which the pH of the gel changes together with the potassium ion concentration. The most positive effect on the separation of the gliadins was generated by a moving front, which is a boundary between regions with a low concentration of K+ ions and a low pH, and region with a high concentration of K+ ions and a high pH, after optimization of the concentrations of the cations and anions in the electrode solutions. The finding was exploited for the development of an extremely simple electrophoresis system, in which buffers were not needed for obtaining a high resolution. The system was further improved by applying a stacking gel. The advantages of this system are discussed. This new approach may be useful for improving electrophoresis systems for other applications.
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  • 22
    ISSN: 1573-5060
    Keywords: alloplasmic line ; breeding ; chromosome ; eyespot resistance ; substitution line ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The variety Roazon possesses genes for resistance to eyespot including that on the 7D chromosome transferred from Aegilops ventricosa. In order to assess the level of resistance due to the latter, we developed the intervarietal substitution for the 7D chromosome of ‘Roazon’ into ‘Courtot’ which is very susceptible to eyespot. As ‘Roazon’ contains Aegilops ventricosa cytoplasm, the substitution lines were produced both with wheat and Aegilops cytoplasm. Resistance was assessed at the seedling and the adult plant stage. No cytoplasmic effect was observed. The substitution lines were as resistant as ‘Roazon’. This shows that the chromosome 7D genes for resistance introduced from Aegilops ventricosa result in a high level of resistance in wheat.
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  • 23
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    Euphytica 44 (1989), S. 143-150 
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat ; Triticum durum ; durum ; environmental correlations ; grain yield ; plant height ; tiller number ; grain size
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Environmental correlation coefficients were computed among all pairs of five traits, namely grain yield, heading date, number of tillers per m2, plant height and 1000-grain weight (grain size) using 30 Triticum durum and 30 Triticum aestivum varieties grown in 18 environments. Grain yield was significantly correlated with the other four traits in almost all of the varieties. The mean correlation coefficient over all varieties ranged from 0.58 to −0.83 for durum wheat and 0.66 to 0.88 for aestivum wheat. The correlation coefficients between heading date and the other traits were also significant, ranging from −0.45 to −0.79 in durum wheat and −0.61 to −0.85 in aestivum wheat. The correlation coefficient between number of tillers with plant height and 1000-grain weight were the smallest, 0.19−0.32 in durum wheat and 0.39−0.60 in aestivum wheat. It was concluded that agronomic practices favouring early and good stand establishment in the dry regions will favour the yield components and important adaptive traits, which contribute towards larger yields. Significant differences were found among genotypes in the environmental correlation coefficients and the associated changes in one trait as a result of changes in other traits.
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  • 24
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat ; Puccinia recondita f. sp. tritici ; wheat leaf rust ; partial resistance ; latency period ; infection frequency ; urediosorus size ; growth stage ; component analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Latency period (LP), infection frequency (IF) and urediosorus size (US) of leaf rust were determined on primary leaves and young flag leaves of 18 spring wheat cultivars. A large growth stage effect and a large cultivar effect on all three components were observed. Partial resistance as measured by the three components was generally better expressed in the adult plant stage than in the seedling stage. Associated variation of the components was observed: long LP, low IF and small US tended to go together. The association was not complete, cultivars with clear deviations of this association for one of the components were found suggesting the existence of at least partly different genetic factors controlling the respective components. LP measured on flag leaves gave the most reliable results and, therefore, could best be used as a selection criterion in breeding programs for partial resistance.
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  • 25
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat ; Puccinia recondita f.sp. tritici ; leaf rust ; temperature sensitivity ; latency period ; infection frequency ; urediosorus size ; growth stage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Three components of partial resistance (PR) were studied at three post-infection temperatures using seven spring wheat genotypes differing in level of PR and two different wheat leaf rust races. The components were latency period (LP), infection frequency (IF) and urediosorus size (US). The expression of LP was more sensitive to temperature than the expression of the other two components. LP-prolonging genes were better expressed at low temperatures than at high temperatures and cultivar differences tended to increase with decreasing temperature in both seedling and adult plant stages. The reaction of IF to temperature differed from that of LP and US, probably because IF is regulated by another mechanism than LP and US. It is recommended to perform PR-screening tests at low rather than at high temperatures. If temperatures are maintained at about 8–13°C (night-day), seedlings can be used to screen for PR instead of the more expensive adult plant tests. The effectiveness of PR in seedling stage at low temperatures suggests that the seedling stage may have epidemiological significance as the low temperatures (8–13°C) are relevant for seedlings in the field.
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  • 26
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    Euphytica 44 (1989), S. 273-282 
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat ; race-specificity ; Puccinia recondita f.sp. tritici ; wheat leaf rust ; partial resistance ; hypersensitive resistance ; latency period ; disease severity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Partial resistance (PR) in wheat to wheat leaf rust (Puccinia recondita f.sp. tritici) is characterized by a slow epidemic build-up despite a susceptible infection type. Two greenhouse tests and two field tests, in which 11 spring wheat cultivars were exposed to five wheat leaf rust races, revealed some indication for race-specificity of PR. In the greenhouse, the expression of PR was highly dependent on the environment. Significant cultivar-race interactions in the first experiment were lost in the second experiment probably due to cultivar-environment and cultivar-race-environment interactions. In the polycyclic field tests several factors played a role in explaining the inconsistency of the cultivar-race interactions, such as differences in initial inoculum, genotypic differences in earliness, interplot interference or environmental conditions. One cultivar-race combination showed a significant but small interaction towards susceptibility in both field experiments. The interaction was probably too small to detect in the monocyclic greenhouse tests. The results do not conflict with the idea that a gene-for-gene relationship could exist between PR-genes in the host and genes in the pathogen. Some problems with regard to the selection of PR in wheat to wheat leaf rust are discussed.
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  • 27
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    Euphytica 44 (1989), S. 241-245 
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat ; Puccinia recondita f.sp. tritici ; leaf rust ; partial resistance ; environmental stability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Five spring wheat cultivars differing in partial resistance (PR) to wheat leaf rust were tested at Wageningen (the Netherlands) on a sandy and a clay site, El Batan (CIMMYT, Mexico) and Ponta Grossa (Brazil) over two years. The cultivars were Skalavatis 56, Little Club (both very susceptible), Westphal 12A, Akabozu and BH 1146 (all three with high levels of PR). The results showed that PR was expressed at all four locations in both years. The level of expression was influenced by the environment but the cultivar ranking was hardly affected. Selection for PR in the field can therefore be carried out over a wide range of environments.
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  • 28
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    Euphytica 44 (1989), S. 247-258 
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat ; Puccinia recondita f.sp. tritici ; leaf rust ; epidemiological parameters ; microfield ; race nursery ; partial resistance ; components of resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Eighteen spring wheat cultivars were tested in microfields and race nurseries for their partial resistance PR to wheat leaf rust under low and high disease pressure respectively. Large differences existed between the 18 cultivars, Skalavatis 56 being the most susceptible and Ponta Grossa 1 being the most resistant cultivar. Of the three epidemic parameters, disease severity (DS) at the time that the susceptible check was severely diseased and area under the transformed disease severity curve (AUTC) and the logistic growth rate (r), AUTC and DS were highly correlated. Both seemed to be reliable estimators of PR but DS should be preferred for economical reasons. The logistic growth rate seemed to be unsuitable as an estimator of partial resistance. High and low disease pressure gave similar cultivar ranking. PR can be screened and selected equally well in race nurseries with low space, low time and low cost input as in microfields with high space, time and cost input. Cultivar differences in development rate had a large impact on the cultivar differences for amount of disease and can therefore greatly bias the estimation of cultivar resistance. The resistance of early cultivars tended to be underestimated whereas the resistance of late cultivars tended to be overestimated. The effect of differences in developmental rate was most pronounced in the flag leaf. It is advisable to avoid the assessment of disease levels on the flag leaf only and to incorporate in the tests several susceptible and resistant checks that cover the range of development rates in the material to be selected, because otherwise selection for resistance will tend to select also for lateness. Regression of the epidemiological parameters on three components of partial resistance revealed that latency period (LP) is an important factor in determining the resistance observed in the field explaining on average 67% of the observed variation. Adding infection frequency (IF) and urediosorus size (US) to the linear model increased the proportion of the observed variation in the field explained by the components to 80%. This result supports the idea that the components of PR inherit independently, at least, in part.
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  • 29
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    Plant and soil 114 (1989), S. 269-278 
    ISSN: 1573-5036
    Keywords: deleterious ; inhibitory bacteria ; pseudomonads ; rhizobacteria ; toxin ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract We studied the production of a toxin inhibitory to both winter wheat (Triticum aestivum L.) root growth andEscherichia coli that was produced by a rhizobacterial pseudomonad. Of several carbon sources tested, the most rapid growth and highest toxin concentrations were obtained with glucose, glycerol, or trehalose. Toxin production was repressed with L-cysteine as the nitrogen source. Toxin was produced during the late exponential and early stationary phase of growth by the bacterium and, contrary to studies with other toxins, was unaffected by Fe and P concentrations in the growth medium. Toxin production by the bacterium was the same at growth temperatures of 25 and 15°C while it produced less at 5°C. If the bacterium was able to grow, it produced toxin. No compound tested induced an increase in toxin production indicating toxin production is constitutive.
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  • 30
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    Plant and soil 115 (1989), S. 83-87 
    ISSN: 1573-5036
    Keywords: karnal funt ; Neovossia indica ; secondary spread ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Wheat-spikes inoculated withN. indica at the boot-leaf stage produced secondary sporidia when later incubated (intact/detached) under moist conditions in the laboratory. Sporidia were also released from inoculated spikes in the field where sporidial release exhibited diurnal periodicity. More sporidia were trapped between 5–6 o'clock than during the later parts of the day but no sporidia were trapped between 14–18 o'clock. However, they could be trapped at any time of the day from the detached spikes incubated under moist conditions in the laboratory. Sporidia trapped in different experiments were invariably of the allantoid type and they proved viable and infective. Maximum sporidia developed on the outer glumes of florets, and this observation was supported by scanning electron microcope studies. Sporidia developed at 15 and 20°C but not at 30°C. These findings indicated that repeated cycles of sporidial production in spikes provided more inoculum than expected from soil-borne teliospores ofN. indica.
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  • 31
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    Plant and soil 116 (1989), S. 29-36 
    ISSN: 1573-5036
    Keywords: cytokinins ; potassium ; seaweed concentrate ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The effects of the seaweed concentrate “Kelpak’ on the growth and yield of wheat grown under conditions of varying K supply were investigated. Kelpak had no significant effect on the yield of wheat receiving an adequate K supply, but significantly increased the yield of K stressed plants. The increase in yield was caused by an increase in both grain number and individual grain weight. Although the beneficial effects of seaweed concentrates have often been attributed to their cytokinin content, several lines of evidence suggested that this group of plant growth regulators may not be solely responsible for the observed effects of Kelpak on wheat. Irrespective of the physiological mechanism of action, Kelpak would appear to have considerable potential for increasing yield in K stressed wheat and may therefore reduce the requirement of wheat for K fertilization.
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  • 32
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    Plant and soil 117 (1989), S. 157-165 
    ISSN: 1573-5036
    Keywords: bacterial metabolites ; gnotobiotics ; growth inhibition ; plant genotypes ; Pseudomonas ; rhizosphere ; Serratia ; symptoms ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract With the aim of elucidating mechanisms behind bacteria-induced deleterious effects and differential cultivar responses to bacterial inoculations, wheat seedlings were subjected to various tests under gnotobiotic conditions. Inoculation with two deleterious Pseudomonas isolates, Å 112 (fluorescent) and Å 313 (nonfluorescent), induced leaf symptoms and shoot and root growth inhibition, while inoculation with growthneutral bacteria (Serratia liquefaciens andEscherichia coli) had no such effects. Deleterious effects were induced at low inoculum densities (〈103 cells per plant), but required addition of nutrient broth in small amounts for consistency. Effects similar to those obtained with living inoculum could be induced by treating plants with sterile culture filtrates from isolate Å 313 or volatile bacterial metabolites from isolate Å 112. Wheat cultivars previously found to differ in their reaction to inoculation under non-sterile conditions, responded differentially to Å 112 and Å 313 also in the gnotobiotic assay. The results agree with the hypothesis that neither cultivar reaction nor the bacterial effects as such are mediated by interactions with an indigenous rhizosphere microflora.
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  • 33
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    Nutrient cycling in agroecosystems 19 (1989), S. 137-142 
    ISSN: 1573-0867
    Keywords: S ; calcite ; dolomite ; soybean ; corn ; wheat ; soil acidity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Liming costs have escalated since the mid 1970's in the United States. Studies of crop response to lime with irrigation are limited as well as those of crop response to soil acidifying agents. This study was conducted to determine yield response of irrigated soybean [Glycine max (L.) Merrill], corn (Zea mays L.), and wheat (Triticum aestivum L.) to lime and S and the change in soil pH, in response to lime and S. Irrigated soybean, corn, and wheat were grown on Dothan and Tifton loamy fine sand (Plinthic Acrisols) with different levels of calcite, dolomite, and S. Soil samples were collected before applying treatments and during each growing season. Soil pH and Mehlich I extractable P, K, Ca, and Mg in addition to grain yield of each crop were determined. Highest soybean yield (4.2 t ha−1) occurred in 1984 at a soil pH of 4.9 (1:1 v/v soil—water suspension) while the yield was zero at a pH of 3.7 on S treated plots. A soil pH of 4.8 in 1985 reduced soybean yield from 3.4 to 2.7 t ha−1 in comparison to untreated plots (pH = 5.6). In 1986, soybean yield was 0.8 t ha−1 at pH 4.0 in comparison to 2.3 t ha−1 at pH 5.1 and 5.9. Corn did not respond to lime with control pH of 5.3 in 1985 or 5.1 in 1986 but S at pH 4.6 reduced yield from 12.3 to 8.7 t ha−1 in 1985 and S reduced yield from 11.0 to 0.9 t ha−1 at pH 4.0 in 1986. Sulfur reduced wheat yield from 4.3 to 1.7 t ha−1 in 1985 and from 2.2 to 0.9 t ha−1 in 1987. Soil pH after cropping with S addition was 4.4 each year. Wheat did not respond to lime when unlimed soil had a pH of 5.2 or above.
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  • 34
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    Plant and soil 113 (1989), S. 213-221 
    ISSN: 1573-5036
    Keywords: microbial biomass ; 32P ; rhizosphere ; soil organic-P ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract 32P-labelled monocalcium phosphate solution was supplied by point injection to the root system of wheat plants grown in soil cores in a controlled environment. There was no detectable incorporation of32P into organic P fractions in the soil remaining after roots were removed, confirming field observations. The techniques used to measure organic P (including biomass P) could detect an incorporation of32P into soil microbial biomass equivalent to 0.3 μgP.g−1 soil, compared to a total soil biomass P content estimated to be ca. 6.5 μgP.g−1 soil. The limited incorporation of the added P into microbial biomass in the root-free soil may be due partly to a limited diffusion of32P into the non-rhizosphere soil and partly to the removal of32P-labelled microbial biomass adhering to or in very close association with the root surface. it is proposed that in studies of soil nutrient status, total soil biomass P (roots + soil flora + microfauna) should be measured, rather than attempting an estimate of microbial P. A sequential extraction procedure using a single soil sample, where a biocide is added to the extracting solution, is proposed as an alternative to the conventional procedure for measuring soil biomass P where two soil samples, one treated with a biocide, are extracted simultaneously.
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  • 35
    ISSN: 1573-5036
    Keywords: Fusarium camptoceras ; Fusarium sp. ; Medicago spp. ; neosolaniol monoacetate ; phytotoxicity ; toxicity ; trichothecenes ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The toxicity of 12 South African isolates of an undescribedFusarium sp. from soil and other substrates was tested in plants and animals. TheFusarium sp. resemblesF. camptoceras but differs in several respects. Two reference cultures ofF. camptoceras were therefore included in the toxicity tests. An isolate ofF. graminearum Gr 1, a known pathogen of annualMedicago spp. (medics) and wheat, was also included in the plant tests. Maize cultures of all theFusarium sp. isolates and oneF. camptoceras isolate were toxic to ducklings. Ethyl acetate extracts of cultures of nine of ten isolates of theFusarium sp. were dermotoxic to rabbit skin. In soil infested with sand-bran inoculum of the fungi, allFusarium sp. isolates, oneF. camptoceras isolate andF. graminearum Gr 1 caused significant (P=0.05) mortality of medics, whereas onlyF. graminearum Gr 1 caused mortality of wheat plants. Seven isolates of theFusarium sp. caused stunting of medic and wheat plants as well as discolouration, necrosis and die-back of the tap root of medics and the primary roots of wheat. The fungus could, however, not be isolated from these necrotic roots. In contrast,F. graminearum Gr 1 that caused discolouration of medic roots and typical crown rot symptoms of wheat, was readily isolated from affected roots and crowns. Maize cultures of isolates of theFusarium sp. and ofF. camptoceras were chemically analysed for neosolaniol monoacetate (NMA), diacetoxyscirpenol (DAS) and T-2 toxin. NMA was detected at levels ranging from 310 to 2060 ng g−1 in 10 of theFusarium sp. isolates, but not in theF. camptoceras isolates. The mortality of medic plants and the NMA yields of isolates of theFusarium sp. in maize cultures were significantly correlated (r=0.84,P〈0.05). A solution containing 10 mg litre−1 of pure NMA was only slightly toxic to ducklings. Exposure of seeds to this solution had no effect on medics and wheat, but exposure of seedlings caused marked mortality in medics and reduction of shoot length in wheat. A solution containing 100 mg litre−1 of NMA was acutely toxic to ducklings, but had no effect on medic and wheat plants when added to soil. Phytotoxic effects on medic and wheat plants were obtained with a concentration of 5000 ng NMA g−1 soil. In all tests, the phytotoxic effects were more drastic in medics than in wheat: medics were killed, whereas wheat seedlings were stunted. This is the first report of the phytotoxicity of NMA to medics and wheatin vivo and probably also the first report of the phytotoxic effects of a pure trichothecene added to soil.
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  • 36
    ISSN: 1573-5044
    Keywords: wheat ; Triticum aestivum ; ABA ; ABA analogs ; somatic embryogenesis ; precocious germination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Zygotic embryos from ten spring wheat (Triticum aestivum L.) genotypes were tested for embryogenic callus induction in the presence or absence of externally supplied (±)-abscisic acid (ABA) and two of its analogs, methyl abscisate and methyl epoxy-beta-ionylideneacetate. (±)-ABA and its analogs suppressed precocious germination of cultured late-stage embryos and promoted embryogenic callus induction. A significantly greater number of plants was regenerated from calli induced in the presence of ABA and ABA analogs. Early-stage embryos when cultured in the presence of (±)-ABA showed a negative response. Possible roles of ABA with respect to the expression of somatic embryogenesis are discussed.
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