ALBERT

Notes: Abstract Enhanced microbial activity following sewage sludge land application may affect soil N cycling and, therefore, plant available N. We studied the effect of anaerobically treated sewage sludge on N-fertilizer efficiency and on some aspects of the soil N cycling. Field plots (3 m × 9 m) sown with barley (Hordeum vulgare L.) in November were amended with a) sludge (80 mg ha-1) and ammonium nitrate (150 kg N ha-1), b) ammonium nitrate (150 kg ha-1) only, c) or left unamended. Monthly soil samples were taken from 0 to 20-and 20 to 50-cm depths to determine soil inorganic N (NH4 +, NO3-). Denitrification in the upper 20-cm horizon was estimated by measuring N2O+N2 emission from undisturbed soil samples by the acetylene-inhibition technique. Crop yield parameters were analysed before harvesting, and grain production was recorded. With respect to the control, the yield increase for the N-fertilizer treatment was 85% and 45% for the sludge + N-fertilizer treatment. The decrease of N-fertilizer efficiency in sludge amended plots was presumably due to a decrease in spring plant available N. Presumably, microbial immobilisation and denitrification in organic amended treatments were responsible for the decrease in N-fertilizer efficiency.

Notes: Abstract A molecular marker map, including Mlo mildew resistance, of the spring barley cross Derkado (Mlo-resistant) × B83-12/21/5 (Mlo-susceptible) was scanned for yield QTLs to determine whether the association of Mlo resistance with reduced yield was due to linkage or pleiotropy. Over the mapped portion of the genome of the cross, the QTL with the greatest effect upon yield was located within a 22 cM region between mlo and the simple sequence repeat HVM67 on chromosome 4(4H). The association of Mlo resistance with lower yield was therefore due to a repulsion linkage. Analysis of yield component characters revealed QTL alleles for reduced grain number and earlier heading date in the same region, also associated with Mlo resistance. Genotyping of a range of cultivars and sources of Mlo resistance with the HVM67 simple sequence repeat showed that the Derkado HVM67 allele was rare as it was found only in one other cultivar and four land-races or sources of disease resistance. Grannenlose Zweizeilige, the source, and Salome, the carrier of Mlo resistance in Derkado, have the same HVM67 genotype, although Salome was a mixture of two genotypes. The entire mlo-HVM67 chromosomal segment from Grannenlose Zweizeilige is therefore thought to have been transmitted to Derkado, possibly through joint selection for Mlo resistance and early heading. L92, synonym EP79, was another source of Mlo resistance with the same HVM67 allele as Derkado but recombination must have occurred during the breeding of Atem as it possesses a different HVM67 allele which is present in all the other Mlo sources and cultivars surveyed. Abbreviations: GN, grains per main stem ear; HD, heading date; MSTGW, thousand grain weight derived from GN and MSY; MSY, yield of grain on the main stem; PY, yield of grain from the whole plot; sCIM, simplified compound interval mapping; SIM, simple interval mapping; SPY, single plant yield; S-SAP, sequence-specific amplification polymorphism; TGW, thousand grain weight derived from bulk of plot seed; TN, number of fertile stems per plant.

Notes: Abstract The generation of AFLPs in spring barley cultivars provided genetic information relating to the development of the crop in the UK since 1953. Principal co-ordinate (PCO) analysis of genetic similarities (gs) confirmed the marked contrast in the cultivars used in the 1970s and 1980s. The earliest cultivars, many derived from Proctor, were succeeded by tall-strawed, disease-resistant types with high yield but poor malting potential. In the 1980s they were in turn replaced by short-strawed cultivars with excellent yield and good malting quality, which originated from Triumph. A PCO plot of gs provided insight into the effects of selection for disease resistance and the antagonism between malting quality and particular resistance genes. The analysis of gs was more useful than pedigrees and estimates of kinship in revealing the genetic relationship between cultivars. Theoretical considerations for maximising the efficiency of an AFLP genotyping programme are discussed in the context of the number of primer pairs required to distinguish genotypes at varying levels of similarity.

Notes: Abstract Barley was milled into flours with extraction rates between 100 and 69%. The nutritive value of the flours was studied by chemical analyses and in balance trials with growing rats. The concentration of essential nutrients decreased when the extraction rate was lowered. The protein content in the 69% extraction flour was reduced to 82% of that in whole barley. Lysine (g/16 g N) decreased from 3.30 in whole barley to 2.82 in the most refined flour, however, the biological value was not significantly affected by the degree of milling. The content of minerals was reduced to 40% of that in whole barley, but only rats fed refined flours were able to maintain their femur zinc concentration. Factors present in the outer part of the kernel interfere strongly with utilization of zinc; and it appears that phytate is not solely responsible for the adverse effects on zinc utilization. In rats fed whole barley, femur zinc could be maintained and protein utilization improved by zinc supplementation. It could be concluded that unless barley is milled into refined products, or zinc is supplied from external sources, zinc utilization is adversely affected and protein utilization is limited by a poor zinc status.

Notes: Abstract The response of seedlings of the monocot Hordeum vulgare L. cv. Bronze to 0,25 and 50 μM aluminium in factorial combination with 0, 1.4, 2.0 and 2.8 mM Si was tested in hydroponic culture at pH 4.5. Nutrient solution (500 μM calcium nitrate) and Al/Si treatments were designed to avoid the precipitation of Al from solution. Silicon treatments gave significant amelioration of the toxic effects of Al on root and shoot growth and restored calcium levels in roots and shoots at harvest to levels approaching those of control plants. Aluminium uptake by roots was also significantly diminished in the presence of Si. Silicon alone gave a slight stimulation of growth, insufficient to explain its ameliorative effect on Al toxicity. The mechanism of the Si effect on Al toxicity in monocotyledons awaits further investigation.

Notes: Abstract The 2,4-dichlorophenoxyacetic acid (2,4-D) degrading bacterium, Burkholderia cepacia (formerly Pseudomonas cepacia) DBO1(pRO101) was coated on non-sterile barley (Hordeum vulgare) seeds, which were planted in two non-sterile soils amended with varying amounts of 2,4-D herbicide. In the presence of 10 or 100 mg 2,4-D per kg soil B. cepacia DBO1(pRO101) readily colonized the root at densities up to 107 CFU per cm root. In soil without 2,4-D the bacterium showed weak root colonization. The seeds coated with B. cepacia DBO1(pRO101) were able to germinate and grow in soils containing 10 or 100 mg kg−1 2,4-D, while non-coated seeds either did not germinate or quickly withered after germination. The results suggest that colonization of the plant roots by the herbicide-degrading B. cepacia DBO1(pRO101) can protect the plant by degradation of the herbicide in the rhizosphere soil. The study shows that the ability to degrade certain pesticides should be considered, when searching for potential plant growth-promoting rhizobacteria. The role of root colonization by xenobiotic degrading bacteria is further discussed in relation to bioremediation of contaminated soils.

Notes: Abstract The establishment of proper agronomical practices and plant breeding programs for saline environments is limited by the lack of adequate field screening methods. We assessed the relationships between leaf ion concentration and grain yield in a set of barley cultivars and compared their ranking for salinity tolerance established with a triple-line-source (TLS) sprinkler system, where the absorption of salts is through the leaves and the roots, with that obtained with a drip-irrigation (DI) system, where the absorption of salts is only through the roots. The saline solution in both systems was made up of sodium and hydrated calcium chloride (1:1 w/w). Except for the highest saline treatments, direct leaf absorption of toxic Na+ and Cl- was minor or negligible, but it was substantial for Ca2+. Irrespective of barley cultivar and leaf age, the accumulation of Cl- in the TLS was 1.5–2.5 times greater than Na+. There was no significant correlation between grain yield and leaf sap ion concentration among eighteen barley cultivars. Thus, leaf ion concentrations should not be used as screening tools in breeding programs for increasing salinity tolerance in barley. The highest-yielding cultivars under non-saline conditions were also most productive under moderately saline conditions, though not under high-saline conditions. Although grain yields of the eighteen barley cultivars in the TLS were substantially lower than in the DI, the salinity tolerances estimated in both systems were significantly correlated (P 〈 0.05), indicating that the simple and inexpensive TLS irrigation system could be successfully used in screening for salinity tolerance in barley.

Notes: Abstract Much effort has been focused on defining the end-point of bioremediated soils by chemical analysis toxicity tests. However, these tests do not assess the quality, or the capability, of soil to support plant growth after bioremediation. We studied the response of plants to hydrocarbon contaminants by camparing barley (Hordeum vulgare) growth on: (i) control soil, agricultural topsoil, (ii) oil-contaminated soil (40,000 mg kg−1 total extractable hydrocarbons, or TEH), and (iii) oil-contaminated soil treated by bioremediation (20,000 mg kg−1 TEH). Barley growth and yield was significantly reduced by oil-contamination. Bioremediation did not improve yield of barley and shoot dry mass was slightly reduced after bioremediation. The lack of effect from bioremediation is attributed to poor soil water sorption, which was negatively influenced by hydrocarbon residuals. We concluded that the soil-water relation is one of the most important factors in assessing endpoint of bioremediated soils for plant growth.

Notes: Abstract To determine the optimum selection environment for barley (Hordeum vulgare L.) targeted at low-input, stress environment, barley lines were selected for high yield under stress (YS), high yield under non-stress (YNS), or average yield in stress and non-stress conditions (YA) during three breeding cycles (cohorts) of three years each. The lines were then tested in a total of 21 year-location combinations with average grain yields ranging from 0.35 to 4.86 t ha-1. Yield under stress of the YS lines was between 27% and 54% higher than that of the YNS lines, with the top YS lines yielding under stress between 16% and 30% more than the top YNS lines. Realized heritability was between 0.35 and 0.67 when selection was conducted under stress and was significant in all three cohorts. By contrast, selection under non-stress gave a significant response in only one cohort, and its efficiency in improving yield under stress was significantly lower than selection under stress. The best YNS line ranked only 19th for yield under stress. The highest-yielding lines under stress were not only selected under stress, but were also landraces collected in very dry areas (〈 250 mm total annual rainfall). This confirms earlier findings and supports the idea that the most effective way to improve productivity of crops grown in less-favored areas is to use locally adapted germplasm and select in the target environment(s).

Notes: Summary We propose that research be increased on chemical restoration of fertility to the genetic male steriles of barley. Seed harvested from male-sterile plants restored to fertility can then be planted as the female for hybrid barley production. Male fertility has been resotred in male-sterile or gynoecious plants by chemicals in many species, but a satisfactory method has not been developed in barley. Male-sterile mutants that self and mutant-chemical combinations with fertility persisting into the second generation should be avoided.

Notes: Summary The effects of N fertilizer, irrigation and location on genotypic and environmental variances of barley and wheat varieties were studied in a series of trials. Genotypic variance for crude protein content, as well as for grain yield, tended to be higher under high N fertilizer rate (80 kg N/ha). The effect of N fertilizer rate on environmental variance varied with variety and location. Increase in crude protein content resulted in decrease in environmental variance for only a few of the varieties tested. The effect of quantity of irrigation water on genotypic and environmental variance for crude protein content was small.

Notes: Summary The cultivar effect on infection frequency (IF) was studied in the seedling and adult plant stages of 15 spring barley cultivars. In both stages the cultivar effects were highly significant. The cultivars L94 and Vada represented the extremes. Vada having about 2 1/2 times fewer uredosori than L94. Between cultivars and development stage clear interactions occurred. Pauline f.i. had the same low IF as Vada in the seedling stage, but in the adult plant stage its IF was about 70% higher. Also other effects could influence the cultivar effects. Increasing leaf age appears to increase IF. The cultivar effect also seemed to depend on the level of IF. At high levels the cultivars differed far less than at low levels of IF. The cultivar effect on IF appeared correlated with partial resistance in the field (r=0.7) through a high correlation with the cultivar effect on latent period (r=0.8).

Notes: Summary Saline soils are typically very patchy in their salinity. The yield of crops growing on them is similarly patchy. This paper argues that because most of the yield from such soils comes from the least saline areas, the best breeding strategy for improving the overall yield of crops growing on them is to select for high yield on non-saline soils. This conclusion derives from comparing the effects that four different breeding goals, namely: (1) a 10% increase in yield on non-saline soils, (ii) a 20% increase in the threshold salinity that first reduces yield, (iii) a doubling of yield at an electrical conductivity of the saturation extract (ECe) of 20 dS/m and (iv) a combination of (i) and (iii), would have on total yield. The effects of achieving these goals in barley, common wheat, durum wheat and triticale in fields exhibiting different salinities are predicted from actual yields of these species grown on different salinities in the field.

Notes: Summary Crosses were made between five cultivars of Hordeum vulgare and three genotypes of H. bulbosum and the influence of male and female partners on success rates up to the stage of haploid embryo culture was investigated. Both parents markedly affected seed setting and rates of embryo differentiation, whereas seed quality was mainly influenced by the female. There was an interaction between certain genotypes when overall embryo culture rates were analysed. Following embryo culture only the influence of the female partner was assessed but differences were found between the H. vulgare cultivars regarding rates of hybrid (VB) production and chromosome doubling whereas total plant regeneration was unaffected.

Notes: Summary Several lines from the cross Akka x Feebar were observed to have β-amylase activity considerably in excess of either parent. It is suggested that, from crosses between two-rowed and six-rowed varieties, two-rowed genotypes with enhanced levels of grain nitrogen and β-amylase activity may be obtained. These can be successfully exploited in a breeding programme to produce barley varities with high diastic power.

Notes: Summary The intergeneric hybrid Hordeum vulgare x Psathyrostachys fragilis was fairly easily obtained. During each growing season the intermediate, perennial hybrid yielded haploid tillers of H. vulgare. Late in one season few, hybrid tillers headed. The morphology, cytology and enzymatic patterns of hybrid and haploid tillers were investigated.

Notes: Summary Simulated segregating barley populations were screened for resistance to scald (Rhynchosporium secalis) in the field at commercial seeding rates. A reduction in infection on the susceptible component occurred with increasing proportions of resistant genotypes. Similar trends were seen in space planted experiments but the use of susceptible buffer rows counteracted the effect, enhanced the infection in susceptible plants and greatly improved discrimination between resistant and susceptible. These results have been applied to the routine testing of F2 populations in the barley breeding programme.

Notes: Abstract Transfer of T-DNA from Agrobacterium tumefaciens and A. rhizogenes to cells of wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) is demonstrated following the inoculation of immature embryos and immature embryo-derived callus. Agrobacterium T-DNA vectors containing the C1/Lc anthocyanin-biosynthesis regulatory genes, the gusA gene or a synthetic green fluorescent protein gene (sgfp-S65T) were constructed from original binary vectors. The visual T-DNA markers were used as cell-autonomous reporters of early Agrobacterium-mediated transformation events in the wheat and barley cells. This localization of the transformed cells revealed a non-random distribution throughout each embryo and callus piece.

Notes: Abstract The effect of varied light intensity (50 – 600 μmol m-2 s-1) on the rate of phytosiderophore release was studied under zinc (Zn) deficiency using a bread (Triticum aestivum L. cv. Aroona) and a durum wheat cultivar (Triticum durum Desf. cv. Durati) differing in zinc (Zn) efficiency and under iron (Fe) deficiency using a barley cultivar (Hordeum vulgare L. Europe). Plants were grown under controlled environmental conditions in nutrient solution for 15 days (wheat plants) or 11 days (barley plants). Phytosiderophore release was determined by measuring capacity of root exudates to mobilize copper (Cu) from a Cu-loaded resin. With increasing light intensity visual Zn deficiency symptoms such as whitish-brown lesions on leaf blade developed rapidly and severely in wheat, particularly in the durum cultivar Durati. In wheat plants supplied well with Zn, increases in light intensity from 100 to 600 μmol m-2 s-1 did not clearly affect the rate of phytosiderophore release. However, under Zn deficiency increases in light intensity markedly enhanced release of phytosiderophores in Zn-deficient Aroona, but not in Zn-inefficient Durati. When Fe-deficient barley cultivar Europe was grown first at 220 μmol m-2 s-1 and then exposed to 600 μmol m-2 s-1 for 24 and 48 h, the rate of release of phytosiderophores was enhanced about 4-fold and 7-fold, respectively. Transfer of Fe-deficient plants from 600 to 50 μmol m-2 s-1 for 48 h reduced the rate of release of phytosiderophores by a factor of 7. The effect of light on phytosiderophore release was similar regardless of whether the rate of phytosiderophore release was expressed per plant or per unit dry weight of roots. The results demonstrate a particular role of light intensity in phytosiderophore release from roots under both Zn and Fe deficiency. It is suggested that in the studies concerning the role of phytosiderophore release in expression of Zn or Fe efficiency among and within cereals, a special attention should be given to the light conditions.

Notes: Summary Genotype-environment interactions in F1 hybrids between a selection of current commereial varicties as male parents and a balanced tertiary trisomic male-sterile female were investigated. Sixteen environments were employed, comprising eight treatments in each of two seasons. Hybrid stabilities in terms of yield response to changing environments, were found to be very similar to those of the parents, however hybrid yields exceeded parental yields in all but one instance. A heterotic effect for plant height was also observed.

Notes: Summary Genotypic frequency data at two loci governing blue vs. white aleurone color in barley showed that composite cross (CC) populations grown at Davis varied in the changes in allelic frequencies as well as heterozygosity levels. The blue class increased steadily over 20 generations in CC V and CC XXI along with an excess of heterozygotes over expected under high selfing rates, fluctuated without a directional shift in CC XIV, and declined in CC XVI. Utilizing the xenia feature of this character, nearly 100 Bl/bl Bl2/bl2 individuals were randomly drawn from the CC XVI and CC XXI populations and used in a paired-plot study of some yield components for comparing the blue and white isogenic classes within lines in the varied genetic backgrounds of different lines. For seed number blue vs. white isogenic class differences were significant only in one out of four populations (CC XXI-F8) whereas differences among the lines were significant in CC XVI-F12, CC XXI-F3 and CC XXI-F8. Thus, specific locus effects were relatively much smaller than the genetic background component although overall the genotypic frequency changes at the aleurone color loci were found to be consistent with the relative average seed output per plant in the three genotypic classes.

Notes: Abstract Twenty homozygous barley lines were grown in row and hill plots at two locations in Ontario in 1973. The hill plots were of two spacings −30×30 cm and 45×45 cm between hills. Within each spacing, three seeding rates were used i.e. 15, 25 and 35 seeds per hill. Grain yield and three of its components, namely; number of seeds per spike (NSS), number of spikes per plot (NSP) and seed weight (SW) were studied. It was concluded that both NSS and SW could be evaluated in hill plots. NSS was found to be an important component of grain yield and its relationship with grain yield was unaffected by plot types and locations. SW also remained unaffected by plot types and seeding rates but as a component of grain yield it was the least important of the three components measured. The correlation between SW and grain yield could be changed by locations. NSP was as important as NSS as a component of grain yield, and was highly correlated with grain yield. Unlike NSS, NSP could not be efficiently evaluated in hill plots since its correlation between row and hill plots was generally lower.

Notes: Summary Eight spring barley cultivars, respresenting the known range in partial or slow rusting resistance to leaf rust, Puccinia hordei, were investigated for their effects on the components of partial resistance; infection frequency, latent period, infectious period and spore production per uredosorus per day. Considerable variation was observed among the cultivars for each of the components. The cultivar effects on the components tend to be associated. Cultivar L94 for instance, shows the highest infection frequency, the shortest latent period and a long infectious period. Julia and Vada both have a low infection frequency, a long latent period and a low spore production per sorus per day. This association, though, is only a partial one. The total spore production per unit leaf area (the combined result of the four components) appeared highly correlated with the partial resistance in the field (r=0.85). Only a relatively small portion of the variation in partial resistance cannot be explained by the four components studied. Several other aspects, which might affect the rate of epidemic development, are discussed. Latent period, measuring the onset of the new spore production, estimated partial resistance as well as total spore production did (r=−0.85). In order to evaluate the partial resistance of barley genotypes in the greenhouse the latent period is preferred above total spore production as it is measured more easily, more accurately and sooner after inoculation.

Notes: Summary The use of ethrel for hand crossing in recurrent selection programs with barley is advocated.

Notes: Summary The latent period (LP) is a crucial component of partial resistance. Five cultivars, L94, Sultan (Su), Volla (Vl), Julia (Ju) and Vada (Va), representing the known range in partial resistance and LP were crossed in a diallel, and the F1, F2 and F3 tested. The LP effectuated by the five cultivars is about 9, 101/2, 101/2, 13 and 151/2 days, respectively. The crosses Su×L94, Vl×L94 and Ju×L94 had an F2 positively skewed. Their F2 means were similar or only slightly larger than the F1 means. The F2 frequency distributions in the crosses Vl×Su, Ju×Su and Ju×Vl were normal or nearly so with F1 and F2 means similar to each other and to the mid-parent value. The crosses involving Va as a parent again showed a positive skewness but with F2 means considerably larger than the F1 moans. Most F2's ranged from the low parent to the high parent values without transgression. In the crosses Va×L94 (reported earlier) and Ju×L94 the parental values were not recovered among 216 and 154 F2 plants, respectively. The cross Ju×Va showed transgression beyond the low parent, Ju. From these data it is concluded, assuming no linkage, that seven loci are involved. The + alleles (governing a longer LP) are thought to be distributed over the parents as follows: % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGceaqabeaacaqGmb% GaaeyoaiaabsdacaqGGaGaaeiiaiaabccacaqGGaGaaeiiaiaabcca% caqGGaGaaeiiaiaab2cacaqGTaGaaeiiaiaabccacaqGGaGaaeiiai% aabccacaqGGaGaaeiiaiaabccacaqGTaGaaeylaiaabccacaqGGaGa% aeiiaiaabccacaqGGaGaaeiiaiaabccacaqGGaGaaeylaiaab2caca% qGGaGaaeiiaiaabccacaqGGaGaaeiiaiaabccacaqGGaGaaeiiaiaa% b2cacaqGTaGaaeiiaiaabccacaqGGaGaaeiiaiaabccacaqGGaGaae% iiaiaabccacaqGTaGaaeylaiaabccacaqGGaGaaeiiaiaabccacaqG% GaGaaeiiaiaabccacaqGGaGaaeylaiaab2cacaqGGaGaaeiiaiaabc% cacaqGGaGaaeiiaiaabccacaqGGaGaaeiiaiaabccacaqGTaGaaeyl% aiaabccaaeaacaqGtbGaaeyDaiaabccacaqGGaGaaeiiaiaabccaca% qGGaGaaeiiaiaabccacaqGGaGaaeiiaiaabccacaqGRaGaae4kaiaa% bccacaqGGaGaaeiiaiaabccacaqGGaGaaeiiaiaabccacaqGRaGaae% 4kaiaabccacaqGGaGaaeiiaiaabccacaqGGaGaaeiiaiaabUcacaqG% RaGaaeiiaiaabccacaqGGaGaaeiiaiaabccacaqGGaGaaeiiaiaab2% cacaqGTaGaaeiiaiaabccacaqGGaGaaeiiaiaabccacaqGGaGaaeii% aiaabccacaqGTaGaaeylaiaabccacaqGGaGaaeiiaiaabccacaqGGa% GaaeiiaiaabccacaqGGaGaaeylaiaab2cacaqGGaGaaeiiaiaabcca% caqGGaGaaeiiaiaabccacaqGGaGaaeiiaiaabccacaqGTaGaaeylaa% qaaiaabAfacaqGSbGaaeiiaiaabccacaqGGaGaaeiiaiaabccacaqG% GaGaaeiiaiaabccacaqGGaGaaeiiaiaabUcacaqGRaGaaeiiaiaabc% cacaqGGaGaaeiiaiaabccacaqGGaGaaeiiaiaabUcacaqGRaGaaeii% aiaabccacaqGGaGaaeiiaiaabccacaqGGaGaaeylaiaab2cacaqGGa% GaaeiiaiaabccacaqGGaGaaeiiaiaabccacaqGGaGaaeiiaiaabUca% caqGRaGaaeiiaiaabccacaqGGaGaaeiiaiaabccacaqGGaGaaeiiai% aab2cacaqGTaGaaeiiaiaabccacaqGGaGaaeiiaiaabccacaqGGaGa% aeiiaiaabccacaqGTaGaaeylaiaabccacaqGGaGaaeiiaiaabccaca% qGGaGaaeiiaiaabccacaqGGaGaaeiiaiaab2cacaqGTaaabaGaaeOs% aiaabwhacaqGGaGaaeiiaiaabccacaqGGaGaaeiiaiaabccacaqGGa% GaaeiiaiaabccacaqGGaGaae4kaiaabUcacaqGGaGaaeiiaiaabcca% caqGGaGaaeiiaiaabccacaqGGaGaae4kaiaabUcacaqGGaGaaeiiai% aabccacaqGGaGaaeiiaiaabccacaqGRaGaae4kaiaabccacaqGGaGa% aeiiaiaabccacaqGGaGaaeiiaiaabccacaqGRaGaae4kaiaabccaca% qGGaGaaeiiaiaabccacaqGGaGaaeiiaiaabccacaqGRaGaae4kaiaa% bccacaqGGaGaaeiiaiaabccacaqGGaGaaeiiaiaab2cacaqGTaGaae% iiaiaabccacaqGGaGaaeiiaiaabccacaqGGaGaaeiiaiaabccacaqG% GaGaaeylaiaab2caaeaacaqGwbGaaeyyaiaabccacaqGGaGaaeiiai% aabccacaqGGaGaaeiiaiaabccacaqGGaGaaeiiaiaabUcacaqGRaGa% aeiiaiaabccacaqGGaGaaeiiaiaabccacaqGGaGaaeiiaiaabUcaca% qGRaGaaeiiaiaabccacaqGGaGaaeiiaiaabccacaqGGaGaae4kaiaa% bUcacaqGGaGaaeiiaiaabccacaqGGaGaaeiiaiaabccacaqGGaGaae% 4kaiaabUcacaqGGaGaaeiiaiaabccacaqGGaGaaeiiaiaabccacaqG% GaGaaeylaiaab2cacaqGGaGaaeiiaiaabccacaqGGaGaaeiiaiaabc% cacaqGGaGaae4kaiaabUcacaqGGaGaaeiiaiaabccacaqGGaGaaeii% aiaabccacaqGGaGaaeiiaiaabUcacaqGRaaaaaa!1BBA!\[\begin{gathered} {\text{L94 - - - - - - - - - - - - - - }} \hfill \\ {\text{Su + + + + + + - - - - - - - - }} \hfill \\ {\text{Vl + + + + - - + + - - - - - - }} \hfill \\ {\text{Ju + + + + + + + + + + - - - - }} \hfill \\ {\text{Va + + + + + + + + - - + + + + }} \hfill \\ \end{gathered} \] The genes are supposed to act additively (intermediate inheritance) with the exception of one locus (the 6th or 7th locus) which shows dominance for the shorter LP (for the-alleles). The effect of this locus on LP seems considerably larger than that of the other loci. There are indications of physiological barriers, which means that LP's shorter than the one of L94 or much longer than that of Va are not possible. The effect of + genes in genotypes governing LP's close to these barriers (with very few or very many + alleles respectively) is smaller than in genotypes governing intermediate LP's.

Notes: Summary A range of leaf rust (Puccinia hordei) isolates was tested on a series of barley cultivars among which the differential series. No resistance to all isolates seems to exist in the cultivated barley. The barley cultivars appear to carry zero to two race-specific resistance (Pa) genes. The isolates carry from three to eight virulence factors from the eight or nine that could be evaluated. Isolates with wide virulence spectra were most common. The pattern with virulence to Pa, Pa2, Pa4, Pa5, Pa6, and Pa8, and avirulence to Pa3, Pa7 and Pa9 is very common and seems to have a near-global distribution. These isolates, however are not necessarily identical in genotype. Partial resistance and race-specific resistance appear idependently of one another in the various cultivars. The increased interest for breeding for race-specific resistance in this host-pahtogen system is on the long term considered a wrong strategy as it will considerably hamper the selection for partical resistance. This resistance is readily available in commercial cultivars and can protect barley from leaf rust damage in most situations.

Notes: Summary Plant regeneration rates from embryos derived from Hordeum vulgare x H. bulbosum were recorded over a 3 1/2 year period. % total plant regeneration (haploids + VB hybrids) varied to some extent but did not seem to be influenced by season or male parent. % VB production (and thus chromosome elimination) was however markedly affected by season and the genotype of the pollinator.

Notes: Summary Polyacrylamide gel electrophoresis (PAGE) of storage proteins (prolamines) was used to screen 64 landraces of wheat and barley from Nepal and the YemenArab Republic and two cultivars for comparison. Altogether 3168 single seeds were examined and the advantages gained by using the vertical slab gel method were recognised. The extent of variation present within populations of landraces could be assessed easily and rapidly using the methods described. Differences in ploidy levels of wheats were detected by PAGE and investigated. Suggestions are made for improvements in sampling strategies in hilly terrain.

Notes: Summary Improvements in the success of doubled haploid production have been achieved partly by screening new accessions of Hordeum bulbosum. In order to assess levels of variation within stocks of this species, rates of embryo differentiation from the cross between H. vulgare × H. bulbosum were recorded for selections derived from two different stocks of H. bulbosum. There was little difference within stocks for this character despite variation in the morphology and banding patterns of two enzyme systems of one of the stocks. It is proposed that to obtain further increases in success rates a few selections from many accessions of H. bulbosum should be screened rather than many selections from a few stocks.

Notes: Summary The barley cultivars Akka, highly susceptible, and ‘Vada’, partially resistant to barley leaf rust, Puccinia hordei, were evaluated for the amount of leaf rust in five experimental field plot situations over three successive years. The field plot situations were: A) plots well isolated from each other by distance and non-leaf rust contributing host plants; B) adjacent plots of 4×41/2 m (18 rows); C) adjacent plots of 4×11/2 m (6 rows); D) adjacent plots of 4×1/4 m (1 row); E) adjacent plots of only one plant (cultivar mixtures). The sporulating leaf area of each plot was measured from samples of 20 tillers taken at random from each plot. In each year the difference in sporulating area between ‘Akka’ and ‘Vada’ was large to very large in the absence of interplot interference in the isolated plots, ranging from 150 to 2100 times. In the adjacent plots the partial resistance of ‘Vada’ was greatly underestimated, 5 to 16 times in the situation B, 14 to 30 times in C, and 75 to 130 times in D and E. Testing lines or cultivars in adjacent plots is the standard procedure in use in breeding programs and in tests of cultivars for their agricultural value. To avoid such under estimation the following procedure is suggested. A few cultivars representing the known range of partial resistance and whose level of partial resistance is well known are evaluated together with the lines and cultivars whose partial resistance has to be assessed. This is demonstrated with a number of cultivars of which resistance values are know from the recommended variety lists for England and Wales. Cultivars have been assessed in Wageningen over four years together with the check cultivars Akka, Sultan, Julia and Vada representing the range of partial resistance with values (on a 1 to 10 scale) of 1, 3–4, 7 and 8 respectively, based on isolated plots experiments.

Notes: Summary A 0–4 scoring system to quantify scald (Rhynchosporium secalis) infection is suggested. Scores 1, 2, 3 and 4 allocated to represent 1/4, 1/2, 3/4 and 4/4 of the crop canopy scalded are easy to comprehend and intermediate scores e.g. 0.5, 1.5, 2.5 and 3.5 give it the breadth of a quantitative scale. Scores on a large number of lines showed a high degree of repeatability and were found to be highly correlated with the log transformed values of the actual leaf area damage. Although it was suggested that predictions of leaf area damage at scores 3–4 should be applied with caution, broad generalization of the scores in discriminating the amount of disease were shown to be soundly based and offered plant breeders a tool to standardize the evaluation of scald resistance in field plots on a large scale with this quick and reliable scoring system.

Notes: Abstract Resistance to net blotch was evaluated in 175 Hordeum vulgare subsp. spontaneum (H. spontaneum) accessions and 149 accessions of thirteen species or subspecies of wild Hordeum. Most H. spontaneum accessions showed resistance to each of the four Pyrenophora teres f. teres (P. teres) isolates tested. However, H. spontaneum accessions showed different resistance reactions, depending upon their origin. In particular, some accessions from Afghanistan and Russia showed a high level of resistance, and accessions from Morocco were susceptible. Among the four P. teres isolates, the virulence spectra on the H. spontaneum accessions were more different between isolates from different countries than between those from the same country. Hordeum spontaneum accessions susceptible to the Canadian isolate WRS102, but resistant to the other three isolates were found in Iraq suggesting the geographical differentiation of resistance genes in H. spontaneum. All accessions of the other wild Hordeum species, especially some accessions of H. marinum subsp. gussoneanum, showed high levels of resistance. These resistance genes may be useful candidates for incorporation into cultivated barley.

Notes: Abstract Two disomic barley chromosome addition lines and five translocated chromosome addition lines of common wheat cultivar Shinchunaga were isolated. They were derived from a hybrid plant between Shinchunaga and cultivated barley Nyugoruden (New Golden) by backcrossing with wheat and self pollination. Barley chromosomes added to chromosome arms involved in the translocated chromosomes were identified by C-banding method and by crossing these lines with Chinese Spring/Betzes addition lines. Two disomic addition lines were identified to have chromosome 6 and 7 of barley, respectively. Two of the five translocated chromosome addition lines were clarified to have same chromosome constitution, 42 wheat chromosomes and a pair of translocated chromosomes constituted with a long arm of chromosome 5B of wheat and a short arm of chromosome 7 of barley. The other three lines could not be identified due to chromosome rearrangement. Performances of these seven lines on agronomic characters were examined. Addition of barley chromosome 7 induced early heading, and chromosome 6 showed lated heading. Almost all of the lines except that of chromosome 6 showed short culm length and all showed reduced number of tillers, spikelets and grains per ear, and low seed fertility. These lines would be useful for genetic analyses in wheat and barley and for induction of useful genes of barley into wheat.

Notes: Abstract Spanish barleys constitute a germplasm group of particular interest for breeding purposes, as Spain has been proposed as a possible centre of origin of the crop. The Spanish National Germplasm Bank (Banco Nacional de Germoplasma, BNG), holds a collection of about 2000 barley accessions, mostly landraces collected in Spain prior to extensive introduction of modern varieties. The objective of this work is to create a core collection of barleys representative of old barley genotypes grown in Spain. The core collection will be constituted by three groups of germplasm: successful old varieties (15); entries in common with previously existing barley core collections (15); and 2-row (8) and 6-row (122) entries from the BNG, for a total of 160 entries. Entries were allocated by stratified sampling in agro-ecological uniform zones of barley cultivation in Spain. Classification of agro-ecological regions for barley was based on historical yield records for Spanish provinces. The number of entries for each region was determined in proportion to the logarithm of historical barley acreage. Final choice of accessions within provinces tried to maximize the diversity and avoid duplications by looking at passport data, and to agronomic evaluation data available for a group of about 900 accessions.

Notes: Abstract Microsatellite (SSR) profiles from 65 wheats and 135 barleys have been generated, involving 14 and 22 loci, respectively. The wheat and barley varieties were chosen to represent the bulk of the area sown to these crops in the UK over the past 70 years. The profiling identified genotypic mixtures in some seed samples. Null alleles were common in wheat, but rare in barley. We describe attempts to increase the efficiency of data acquisition. High resolution agarose gel electrophoresis was unable to satisfactorily resolve 1–2 repeat unit differences in the common size range for SSR loci, and was therefore unsuitable for mass screening of allelic variants. Multiplex PCR was very dependent on the choice of primer combinations and seldom produced amplifications as consistently as when primer pairs were used individually. Background (non-specific) amplification was common to many primer pairs, and this hindered the use of both multiplex PCR and multiple sample loading. Sequential sample loading was the most effective strategy, although this was the least time-efficient of the measures used.

Notes: Abstract The paper describes a methodology to incorporate the collection of barley landraces available in the Plant Genetic Resources Centre of Ethiopia (PGRC/E), as well as future collections, in the Ethiopian barley breeding program. Six hundred pure lines extracted from thirty Ethiopian barley landraces were evaluated and selected, along with the original populations, between 1989 and 1993. Three lines were identified which significantly outyielded the local landrace in some of the testing sites and had a higher average yield across sites and seasons. The yield of these lines was similar to the best improved variety also developed from a landrace population. Despite the relatively small number of landrace-lines (600) in the original population, the exploitation of the diversity existing within Ethiopian barley germplasm has produced in only five years promising lines for yield at low input conditions and for disease and insect resistance. Some lines had a yield potential comparable with the best breeding lines produced earlier, and one is under multiplication for release.

Notes: Abstract The recovery in crop and soil of labelled fertilizer nitrate applied to barley and maize growing on a sandy soil was measured. The experimental plots, each measuring 4m × 4m, were situated on fields growing with barley and with maize. The barley received 50 kg N/ha as KNO3 enriched with 5.99 At.%15N excess while the maize received 113 kg N/ha as KNO3 labelled with 5.014 At.%15N excess. Otherwise, the plots were treated the same as the rest of the field. At harvesting, the barley and the maize plots were subdivided into nine and six sub-plots respectively. Plant samples, including the roots and soil samples up to 1 m depth were collected in each sub-plot. Fertilizer N recovery in the samples was measured. In the plants, the N derived from the fertilizer (Ndff) was 24.0% and 16.7% in barley and maize, respectively. The percentage of the applied fertilizer recovered by barley was 57%; for maize, only 18%. The movement of fertilizer N was restricted to the top 50 cm in the barley plot, whereas in the maize plot, the fertilizer N could be detected down to 90 cm. The amount of fertilizer N remaining in the soil at harvest was 32% for the barley and 68% for the maize plot. The loss of fertilizer N under barley was 10% and 14% under maize. The loss was attributed mainly to denitrification. The means and the variances of total N uptake by plants inside the15N plot and outside the15N plot were compared. They did not differ significantly, indicating that the results obtained from the15N plot can be extrapolated to the rest of the field.

Notes: Abstract A methodology to quantify N fertilizer requirement for a barley crop is proposed. The method consists of establishing a relationship between barley N demand (DEM) and an index of soil N supply (NS). NS values were obtained adding the inorganic N, i.e, (N-NO- 3 + N-NH+ 4, (Ni), measured just before planting in the soil to an index of soil N mineralization (Nor): NS = Ni + Nor Soil organic matter (SOM) was selected as an index of Nor: Nor = 25.9 + 17.9 (SOM) R2; = 0.89; p 〈 0.01 and Ni was measured in a soil extract obtained with KCl (1N). Ns values were related to both grain yield (Y) and N accumulated in the above ground biomass of barley (AB) grown under greenhouse conditions. The following relationships were obtained: Y = 0.81 + 0.99 (NS) - 0.0002 (NS)2 R2 = 0.77; p 〈 0.01 AB = -0.006 + 0.002 (NS) - 0.000003 (NS)2 R2 = 0.84; p 〈 0.01 A graphic relationship was established between DEM and NS, in order to extrapolate the greenhouse results to field conditions. Using this relationship, AB was converted from g N pot-1 to kg N ha-1, and NS from μg g-1 of N in the soil to kg ha-1.

Notes: Abstract Effects of black locust (Robinia pseudoacacia L.) on productivity and N nutrition of barley (Hordeum vulgare L.) were evaluated under various management regimes (2 soil types, 3 levels of N fertilizer, and 3 cropping systems — barley alone, and barley intercropped with trees pruned or unpruned). Intercropping did not affect productivity and N nutrition of barley in 1988 when trees were small. However, there was a significant yield decline in 1989 as the trees grew bigger. On average, productivity of the sole crop was 8% higher in both soil types. Pruning and mulching moderated the yield reduction compared with the unpruned treatment. Competition for soil moisture was considered a major constraint. Nonetheless, the overall productivity (barley+black locust) from the intercropped treatments was 53% higher than sole cropping. In 1989 and 1990, intercropped barley had significantly higher grain and straw N concentrations (%). In 1989, for example, grain N content was 11% higher than in the sole crop. Removal of trees in 1990 resulted in significant increase in productivity and N content of subsequent barley crop relative to continuous sole cropping. From N nutrition viewpoint, barley from previously intercropped treatments showed superior quality and it had, on average, 23% higher grain N content than the sole crop. This was attributed to N2-fixation and N return by black locust. It was estimated that black locust contributed about 36 kg N ha−1 to the system. This study underscores the role black locust is potentially capable of playing in the development of sustainable and low-input agricultural systems in temperate regions. Nonetheless, the study also illustrates the importance of the below and above-ground interactions that occur in intercropped systems and the need for further research in this area.

Notes: Abstract Through proper design and management of a tree-based intercropping system, ‘competitive’ interactions can be reduced and ‘complementary’ interactions promoted so that tree and crop components maximize sharing of resource pools. In this experiment, main and interaction effects of three levels of soil moisture (15 KPa, 15–50 KPa and 15–300 KPa) and three levels of soil N (35, 70 and 140 kg N ha−1), on growth, development and yield of intercropped poplar (Populus spp.) clone DN 177 and barley (Hordeum vulgare, var. OAC Kippen), were investigated in a potted greenhouse experiment. Barley growth and development and grain yield were significantly (p〈0.05) affected by the levels of soil moisture and N tested but, growth and development of poplar was not. Moisture and N levels contributed their maximum effect to final grain yield when the other was presented in adequate quantities. However, the treatment combination of highest levels of moisture and N did not significantly affect the grain yield when compared to the combination of medium levels of moisture and N. It appears therefore that an increase in the level of moisture and N beyond an optimum level is not likely to significantly affect final grain yield or above ground biomass. There was no difference in the final grain yield or other parameters between the monocropped and intercropped barley, suggesting that poplar did not compete for moisture or N with barley. The total aboveground biomass produced per pot in the intercropped system was 14% higher than in the monocropped system. As there was no difference in the final grain yield, the tree intercropped treatment has an advantage over monocropped systems in terms of resource utilization.

Notes: Abstract The role of 5-aminolevulinic acid (ALA) as a precursor of chlorophyll or a herbicide is well documented. In the present report, to elucidate the physiological effects of ALA, this compound was applied to the foliage of radish at 0.06, 0.18, 0.6, 1.8 and 6 mM. ALA at 0.06ndash;1.8 mM increased the dry weight of radish root (underground part), but injured radish seedlings at 6 mM. Also, the application of ALA at 0.18 and 0.6 mM increased fixation of CO2 in light and decreased release of CO2 in darkness. Furthermore, the effects of foliar treatment of ALA on the yield of several crops were also evaluated. The results showed that an application of ALA at low concentrations increased the growth and yield by 10ndash;60percnt; over the control on kidney bean, barley, potato and garlic. These results suggest that ALA has plant growth regulating properties at low concentrations and may enhance agricultural productivity.

Notes: Abstract Five isozyme and endosperm reserve protein systems were analysed using electrophoretic techniques in order to investigate the genetic diversity of 222 accessions of Spanish, local varieties of barley, Hordeum vulgare L., maintained at the Centro de Conservación de Recursos Fitogeneéticos of the I.N.I.A. (Alcalá de Henares, Spain). The esterase (EST) isozymes provided more information than did the other systems analysed, showing a total of 14 variable markers. The cathodic peroxidases (CPX) and acid phosphatases (ACPH) were also polymorphic. Malate dehydrogenase (MDH) and glutamate oxaloacetate transaminase (GOT) were monomorphic. The hordeins showed patterns of up to 15 bands, the majority of which were very useful in distinguishing genotypes. 17.2% of accessions showed a uniform genotype, 29.8% showed practically identical genotypes and 53% showed mixtures of different genotypes. It is noteworthy that the use of only two systems (EST and hordeins) and the analysis of only six loci (Est-1, Est-2, Est-4, Hor-1, Hor-2 and Hor-3) is sufficient to reveal the genetic diversity of the collection.

Notes: Abstract To study genetic variation in crossability, 80 barley accessions of diverse geographic origin consisting of 50 wild barleys (H. vulgare ssp. spontaneum or ssp. agriocrithon) and 30 cultivated barleys (H. vulgare ssp. vulgare) were crossed as the male parent with a highly crossable wheat variety, Shinchunaga. Crossabilities, expressed as the percentage of pollinated florets giving embryo-containing caryopses, ranged from 0% to 68.6%. Barley accessions from East Asia had generally a low crossability, while barley accessions from other regions exhibited a wider range of crossability including highly crossable genotypes. No significant difference in mean crossability was found between wild and cultivated barleys. To estimate the number and location of barley genes controlling the crossability, doubled haploid lines derived from the cross between the barley varieties Steptoe and Morex were crossed as the male parent with wheat. Quantitative trait loci (QTL) analysis using molecular markers identified four QTL. These were mapped to the centromeric regions of chromosomes 2H, 3H and 5H and the short arm of chromosome 7H. The QTL on chromosomes 3H and 5H had larger effects than those on chromosomes 2H and 7H. The four QTL collectively explained 35.4% of the total variance under a multiple QTL model. Relationships of the QTL identified in the present study with previously reported crossability genes of barley and wheat are discussed.

Notes: Summary Several experiments have been performed in order to induce cell proliferation and plant differentiation from pollen grains by anther culture in barley. Some modifications of the culture media, pretreatments and transfer of the anthers increased notably the frequency of cell division, but the low proportion of normal green plantlets differentiating from microspores and calluses remains the major obstacle preventing the practical use of anther culture in barley breeding.

Notes: Summary Single plants of 12 barley (Hordeum vulgare L. and H. distichum L.) cultivars were randomized to form simulated segregating (mixed) rows. There were 16 mixed rows 15 cm apart, each row containing 24 plants 5 cm apart. In addition, every third row was a control row of one of the cultivars, Bonanza. Each plant was harvested separately. The cultivars differed significantly for all seven characters measured. These seven characters fell into 3 performance groups. Group I characters, seeds/head, 1000 kernel weight, days to ripe and height, showed a higher variance in the mixed rows than in the control rows, had high average heritabilities, and were consistent in performance from one row to another when measured by correlation amongst the cultivars. In Group II, yield/plant and seeds/plant, variance, heritabilities and performance consistency were all low or non-significant. Group III, heads/plant, fell between Groups I and II. These results suggested that single plants with the desired genotype could be successfully selected for characters in Group I only. The frequency with which the most desirable genotype would actually have been chosen with 12.5% selection intensity generally confirmed the above conclusions but indicated that the degree of differences among genotypes was also important in selecting the most desirable genotypes.

Notes: Summary Four cultures of Puccinia hordei isolated from the alternate Ornithogalum hosts in Israel were virulent on seedlings of barley cultivars carrying resistance genes Pa, Pa2, Pa2 + Pa5, Pa2 + Pa6, Pa3, Pa4, and Pa7. Cultures with such a spectrum of virulence have never been reported. The cultures remained stable through 20 successive inoculation and isolation cycles. One of the cultures, T-40SS, retained its specific virulence after selfing on the alternate host. The evolution of virulent races of obligate parasites in the centers of origin of their hosts is discussed.

Notes: Summary Barley plants are able to accumulate glycinebetaine (betaine) at high levels in their leaves in response not only to water and salt stress but also to cold stress. Such accumulation of betaine during acclimation to cold is associated to some extent with freezing tolerance in leaves of barley plants, as previously demonstrated with near-isogenic lines that differed only in a single gene for the spring type of growth habit (Plant, Cell and Enyironment 17: 89–95, 1994). We now present evidence that the levels of betaine accumulated during cold acclimation might be associated with the earliness or lateness of the maturity of cultivars, namely, that late cultivars accumulate more betaine than early cultivars. Moreover, the grade of the vermalization requirement of the cultivars seemed unlikely to be associated with the level of betaine acumulated during cold acclimation. However, the trait that controlled accumulation of betaine during cold acclimation was not linked with the earliness or lateness of the maturity of cultivars. The higher levels of betaine in the late cultivars might have resulted from co-selection for lateness of maturity and freezing tolerance, which is generally a requirement in the areas of Japan where such late cultivars were originally cultivated.

Notes: Summary Several crossing series including the hexaploid (2n=6x=42), South American speciesHordeum lechleri and diploid (2n=2x=14) cultivated barley (H. vulgare) were performed. Barley functioned better as the paternal than as the maternal parent in all cases. Viable offspring were only obtained from one hybrid combination when barley was used as the maternal parent. There was an environmental influence on the success of crosses. A high seed set was counteracted by a lower germination frequency. The outcome is that different crossing series give similar results. As a result of chromosome elimination and in a few cases duplication of especially the barley chromosomes, the chromosome numbers of the offspring (239 plants) varied from 2n=21 (trihaploids ofH. lechleri) to 2n=30. Fifty-five % of the plants were euploid with the number expected for a hybrid (2n=28). The frequency of hyperploids, euploids, hypoploids (2n=22–27) and trihaploids varied by year, locality, type (winter/spring) of barley,H. lechleri population, and crossing direction.

Notes: Abstract Exotic germplasm may be useful for the improvement of agronomic performance of barley breeding material. This study was conducted in order 1) to evaluate if it is possible to improve performance of Nordic barley breeding material by utilizing exotic germplasm sources (unadapted landraces and H. spontaneum), 2) to evaluate incorporation of exotic germplasm into a genetic base widely adapted to the agro-ecological conditions of the extreme Scandinavian north as well as to the base adapted to the conditions of the south of this geographical region, and 3) to evaluate whether an index composed of several traits corresponded to 'breeder's phenotypic evaluation' of the progenies. Earliness, straw length, number of ears/plant, yield/plant, seed shattering, persistence of awns and an index computed from these traits were studied in Swedish and Finnish 4-way crosses along with their adapted parents. Most of the crosses headed earlier than their adapted parents and none of the crosses outyielded the adapted parents. The most favorable frequency distributions for the index were found in the crosses with only cultivated barleys as parents. Transgressive segregates were also found in progenies with H. spontaneum parents. Incorporation of exotic barleys was most successful into the local genetic base. Comparisons between indices and breeder's phenotypic evaluation suggested reconsideration of evaluation methods early in parent development.

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.

Notes: Abstract Selection and breeding of crops for aluminium (Al) tolerance is a useful approach to increase production on acid soils. This requires a rapid and reliable system to discriminate between Al-tolerant and Al-sensitive genotypes. A hydroponic system was developed to screen for Al tolerance in barley (t Hordeum vulgare L.) to overcome several problems encountered in previous screening methods. Four levels of Al (5, 10, 20, and 40 μt M) in 1 mt M CaCl2 solution at pH 4.5 were used to rank lines for Al-tolerance. Each line was cultured in a different compartment to eliminate chemical and pH interactions among lines. To avoid changes in Al tolerance due to other factors such as the calcium (Ca) concentration of the solution, Al-tolerant (Atlas 66) and Al-sensitive (Scout 66) cultivars of wheat (t Triticum aestivum L.) were used as reference cultivars. Five ranks of Al tolerance from highly tolerant to highly sensitive were established by comparison with each reference. Eriochrome cyanine R staining was used for the rapid evaluation of Al tolerance. This screening system allowed classification of about 50 barley lines into five different Al tolerance groups within one week. Using this system, screening of ca. 600 barley lines from various regions of the world was conducted. Most lines were sensitive to Al, but ninety lines showed intermediate Al-tolerance. Thirty nine lines were highly sensitive to Al in solution.

Notes: Summary Crosses in spring barley between parental combinations classified by their G x E interactions as ‘similar’ or ‘dissimilar’ were compared for both the expression of heterosis in F1 and for the amount of variation released in F2. Such classification could not reliably identify the most heterotic F1 hybrids, but F2 variation was generally higher in the ‘dissimilar’ cross combinations. Examination of yield components of parental and F2 populations further showed that yield of single plants was affected primarily by tiller number, which was generally not heritable in F2. Single plant selection was suggested to be most useful when based on grain number per ear.

Notes: Summary Six wild barley (Hordeum spontaneum) accessions, from a diverse range of habitats, and two spring-cultivated barleys, were examined for variation in durations of development phases. The durations of the leaf initiation and spikelet initiation phases were longer and spikelet growth phases shorter, in wild than in cultivated barley. Across all wild and cultivated barleys the rate and duration of spikelet initiation were negatively correlated, but neither was related to the number of spikelets per spike. The number of spikelets was positively correlated with the number of leaves and the ratio of the number of spikelets to the number of leaves declined with increasing time to anthesis, indicating that each successive leaf was associated with a diminishing increase in the number of spikelets. The duration of culm elongation and final culm length were shorter in accessions of cultivated barley compared with wild barley. This paper also discusses the feasibility for increasing the number of spikelets per spike through breeding for genetic changes in lengths of pre-anthesis phases of development.

Notes: Summary Under drought conditions seminal roots may be more important than nodal roots and plants often reach maturity growing with their seminal roots only. This study was conducted to assess the differences, at an early stage of development, for seminal root characteristics and coleoptile length in three groups of barley germplasm: H. spontaneum, landraces, and modern cultivars. H. spontaneum had an average of three seminal root axes, always less than modern varieties and landraces, intermediate maximum seminal root length, and total root length similar to that of modern germplasm. Landraces did not differ from modern cultivars for number of seminal root axes, but they had the longest seminal root system. Modern cultivars had several short seminal roots. The results suggest that landraces have a more vigorous seminal root system than modern cultivars. Both landraces and H. spontaneum are important genetic resources which may contribute to specific adaptation of barley to moisture-stressed environments.

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.

Notes: Summary The genetic basis of resistance to scald (Rhynchosporium secalis) within barley breeding populations is poorly understood. The design of effective genetically based resistance strategies is predicated on knowledge of the identity of the resistance genes carried by potential parents. The resistance exhibited by a broad selection of western Canadian barley lines was investigated by evaluating their reactions to five R. secalis isolates. Results were compared to the resistance exhibited by previously characterized lines. This comparison, combined with pedigree analysis indicated that there are two different resistance genes present inwwestern Canadian cultivars. These genes were shown to be independent through analysis of a segregating population derived from a cross between Falcon and CDC Silky. This evidence, along with observed linkage of the gene in CDC Silky with an allele specific amplicon developed for a Rhynchosporium secalis resistance locus on chromosome 3, provides evidence that the gene in Falcon is the Rh2 gene derived from Atlas, and the gene (s) in CDC Silky is located within the Rh/Rh3/Rh4 cluster and is similar to the Rh gene in Hudson.

Notes: Abstract Auto- and alloplasmic doubled haploid (DH) lines of barley were examined for susceptibility to Fusarium culmorum (W.G.Sm.) Sacc. (isolate KF350) seedling blight. Inoculated kernels were incubated at 20 °C in a chamber saturated to 100% RH a with 12/12 h dark/light cycle. Germination capacity, disease score on a 5-degree scale and root length were evaluated. The data were analysed statistically using three-factor analysis of variance. It was observed that the infection score of roots of DH lines with H. bulbosum cytoplasm was higher than that of their autoplasmic analogues. Length of infected seedling roots expressed as per cent of the control root length ranged from 81 to 56% in autoplasmic DH lines and from 60 to 48% in alloplasmic lines. These differences were statistically significant (at P = 0.01). It was evident, that H. bulbosum cytoplasm increase susceptibility of barley genotypes to Fusarium seedling blight.

Notes: Abstract Resistance to Pyrenophora teres Drechs. f. teres Smedeg., the net blotch pathogen, was studied in six 6-row Nordic spring barleys (Hordeum vulgare L.) in the field and in the greenhouse. The barley genotypes were: Arve, Agneta, Artturi, H6221, Pohto and WW7977. Disease progress was monitored in the field (1994 and 1995) in small artificially infected plots, sown at commercial seeding rates, and in infected hill plots (1994). Areas under the disease progress curves (AUDPC) and apparent infection rates (r) were calculated for the uppermost 3 or 4 leaves. Terminal severities (TS) were also recorded. Infection response of seedlings to a range of P. teres isolates was assessed in the greenhouse using a standard scale. In small plots in the field, Arve and Agneta were very susceptible to P. teres infection, as indicated by large values for AUDPC and TS. H6221 and WW7977 were highly resistant, while Artturi and Pohto were moderately resistant. In hill plots the situation was similar, except that Artturi and Pohto appeared less resistant than in the small plots. The relatively greater resistance of H6221 and WW7977 was reflected in seedling infection responses. According to the results of these experiments, H6221 and WW7977 possess adequate levels of quantitative resistance to P. teres to make them useful parents in future crossing programs aimed at improving net blotch resistance in Finnish spring barleys.

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).

Notes: Abstract A striking relation has been shown between the increase of glutathione levels during dormancy breakage of barley seeds and the induction of germination by exogenous glutathione. These findings suggested that glutathione may play a crucial role in dormancy breakage.

Notes: Abstract This paper describes the isolation of the cDNA encoding a protein previously shown to be indicative of the disease-resistance phenotype mediated by the Yd2 gene in barley (Hordeum vulgare L.). Amino acid sequences of four peptides obtained after isolation of the protein on two-dimensional polyacrylamide gels were completely homologous to sequences occurring within subunit E of barley vacuolar proton-translocating ATPase. Nucleotide sequence data of cloned cDNAs from both Yd2 and non-Yd2 barley varieties showed an amino acid change arising from a single-base-pair polymorphism. This was predicted to result in the shift in isoelectric point used previously to differentiate the protein in Yd2 and non-Yd2 barleys. Earlier work had indicated very close linkage between the gene from which this cDNA is derived, which we have named Ylp, and Yd2, the barley yellow dwarf virus resistance gene. We report here the development of PCR-based assays which discriminate between the two alleles of Ylp and thereby act as valuable predictors of Yd2 for barley breeders and others looking to study this important gene in cereal crops. The validity of each assay was tested with an extensive survey of over 100 barley varieties currently under cultivation in Australia or of importance to Australian barley breeding programmes. Complete agreement was observed between the allele of Ylp detected by the assay and the known Yd2 status of the barleys. A dominant PCR marker for the Yd2-associated allele of Ylp was subsequently developed using an allele-specific primer pair. This fast and economical assay will have broad application in the marker-assisted selection of Yd2-containing lines.

Notes: Abstract The use of reporter genes to characterise sequence elements that act to regulate gene expression in transgenic plants has been vital to the development of foreign gene expression strategies for use in cereal transformation. ThegusA locus ofEscherichia coli, which encodes the enzymeβ-glucuronidase (GUS), is by far the most popular reporter gene used in plant transformation. In this paper we extend the utility of the GUS reporter gene system in cereal transformation by describing and evaluating a number of novel constructs suitable for use in direct gene transfer experiments. These plasmids are all available from the Molecular Genetic Resource Service of the Center for the Application of Molecular Biology to International Agriculture.

Notes: Abstract A consensus linkage map of the barley genome was constructed. The map is based on six doubled haploid and one F2 population. The mapping data for three of the doubled haploid populations was obtained via the GrainGenes database. To allow merger of the maps, only RFLP markers that produce a single scorable band were included. Although this reduced the available markers by about half, the resultant map contains a total of 587 markers including 87 of known function. As expected, gene order was highly conserved between maps and all but two discrepancies were found in closely linked markers and are likely to result from the small population sizes used for some maps. The consensus map allows the rapid localisation of markers between published maps and should facilitate the selection of markers for high-density mapping in defined regions.

Notes: Abstract Intron sequences from monocotyledonous and dicotyledonous origin were used to abolish marker gene expression in prokaryotes (Escherichia coli and Agrobacterium tumefaciens) but permit expression in selected eukaryotic systems using the eukaryotic specific splicing mechanism. A 1014 bp maize Shrunken-1 (Sh 1) intron 1 flanked by exon1 and exon2 sequences was cloned into the N-terminal of the NPT II-coding region. Transient gene expression analysis revealed that the modified neomycin phosphotransferase II (NPT II) gene, driven by the cauliflower mosaic virus (CaMV) 35S promoter, is expressed in barley protoplasts, but poorly expressed in tobacco protoplasts. In dicotyledonous cells AU-rich sequences are known to be important for efficient splicing and therefore an attempt was made to improve expression of the NPT II gene, containing the Sh 1 intron 1, in tobacco by increasing the AU content from 57% to 69%. Reverse transcriptase PCR analysis of RNA from transiently expressed NPT II transcripts from tobacco protoplasts revealed that despite the increase in AU-content, NPT II was still poorly expressed. Cryptic splice sites were identified as one possible cause for missplicing of the Sh1 intron 1 in dicots and poor levels of expression. Alternatively, cloning of the 198 bp intron 2 of the potato STLS 1 gene (81% AU) into the N-terminal part of the NPT II-coding region resulted in proper expression of NPT II in tobacco as well as in barley protoplasts and abolished marker gene expression in prokaryotes. The successful insertion of an intron into a selectable marker gene which completely abolishes gene expression in prokaryotes, without affecting expression of chimeric genes in monocotyledonous and dicotyledonous plant cells provides a suitable system to reduce the number of false-positives in transgenic plant production.

Notes: Abstract In March 1991, large chlorotic patches appeared in an autumn-sown barley crop growing near Thessaloniki, Greece. Leaves had characteristic mosaic symptoms and immunosorbent electron microscopy and enzyme-linked immunosorbent assay confirmed the presence of both soil-borne mosaic viruses of barley, barley mild mosaic and barley yellow mosaic bymoviruses. In the following year, similar symptoms appeared in a crop at Souroti, 30 km east of Thessaloniki but the disease has not been found in other areas of Macedonia. This report is the first record of these viruses from Greece and is the most southerly European record.

Notes: Abstract The temperature requirements of three single cystosorus strains of Polymyxa sp. from India were studied at 15–18, 19–22, 23–26 and 27–30 °C (night-day temperature), and compared with the temperature requirements of three strains of P. graminis from Belgium, Canada and France and two strains of P. betae from Belgium and Turkey. Sorghum was used as the host-plant for the Indian strains; the strains of P. graminis and P. betae from temperate areas were cultivated on barley and sugar beet, respectively. The cystosori germination and the development of plasmodia, zoosporangia and cystosori of Polymyxa sp. from India were optimal at 27–30 °C. Infection progression was slower at 23–26 °C than at 27–30 °C. At 19–22 °C, infection was insignificant. No infection occurred below 19 °C. In contrast, the infection of barley with P. graminis strains from temperate areas was optimal at 15–18 °C, but at 19–22 °C the progression appeared inconsistent and infection stayed low. Above 22 °C, infection was insignificant. P. betae strains showed consistent infection in the range of 15–18 °C to 27–30 °C. Plasmodia formation and cystosori detection of the Belgian strain were slightly advanced at 23–26 °C compared to 19–22 °C but clearly restrained at 27–30 °C. Fungus development of the P. betae strain from Turkey was almost as high at 27–30 °C as at the lower temperatures. These results strengthen the case for distinguishing between Polymyxa sp. from India and P. graminis or P. betae from temperate areas.

Notes: Abstract Seven spring wheat, 13 barley, 14 oats and 20 winter wheat genotypes were inoculated at flowering in 1993 and 1994 with mixed conidial suspensions of 8 isolates of Fusarium culmorum. Four weeks after inoculation, head blight was recorded in the field. After harvest, seed infection was assessed by a Freezing Blotter Test in the laboratory. Seed samples were also analyzed for deoxynivalenol (DON) content. Differences were found in head blight rating, the levels of infected seeds and the DON content between wheat, barley, and oats and between cultivars. Highly significant correlations were found between the percentage of heavily infected seed and the DON content. The weighted mean value of infected seeds and DON content were also significantly correlated. No significant correlation was found between head blight rating in the field and DON content. The level of infected seeds, as determined by the Freezing Blotter Test, was a better indication of the DON content in the seeds than the head blight rating. This visual assessment of levels of infected seeds gives a reliable estimate of resistance to Fusarium.

Notes: Abstract The mass fractal dimension (MFD) of colonies of mildew (Erysiphe graminis f.sp. hordei) growing on barley was calculated as a measure of their spatial structure. Despite the elongated shape of the colonies imposed by the leaf cellular structure, the MFD remained constant with scale. The mildew MFD differed on different cultivars of barley, and was greater on leaves produced under higher nutrient level indicating a physiological component. Lower MFD values correspond with the thin spreading growth associated with exploration strategies and higher values correspond to the denser, more branched structure associated with exploitation of the substrate. Cultivars showing exploration strategies induced by resistance expression responded to increased nutrient levels more than those expressing little resistance such as Golden Promise.

Notes: Abstract Powdery mildew populations were analysed to determine the effects of a resistance elicitor and cultivar mixtures on genetic complexity and diversity. Isolations were made from a range of spring barley monocultures and mixtures in a field trial, and characterised for virulence and RAPD profile. In a second trial, isolates were taken from a single mixture from untreated and resistance elicitor-treated areas and from the components of the mixture in monoculture. The mildew population was not only highly heterogeneous for virulence characteristics, but also proved heterogeneous within pathotypes for molecular markers, indicating the major impact of sexual recombination on population structure and the lack of clonal dominance. Various diversity measurements were compared and the value of dissimilarity measurement for revealing genetic distance within a population was highlighted. There was a trend towards increasing complexity as the season progressed, but there was no consistent relationship between cultivar or mixture, disease control treatment, fertiliser treatment, replicate or position in trial, and pathogen genotype. Whilst the resistance elicitor did reduce mildew by 78% in the first trial, and there was no interaction with fertiliser level in its expression, control was substantially less in the second trial. There were no differences between mildew isolates from elicitor and control treatments. It was felt that more effective and consistent resistance elicitors need to be developed before it can be stated that they are unlikely to be eroded by selecting resistant or adapted mildew genotypes.

Notes: Abstract Forty-four bacterial isolates were obtained from infected wheat, barley and various grasses from different regions of Iran. All isolates were bacteriologically similar toXanthomonas campestris and some of their physiological and biochemical features can be useful for a primary differentiation between them. Depending on their pathogenicity, the isolates were split into two groups; the wheat group isolated from wheat, barley and grasses could infect artificially wheat, barley, rye,Agropyron elongatum, Bromus inermis, andLolium multiflorum but not oat, whereas the barley group obtained from cultivated or wild barley was pathogenic to barley only. From their bacteriological characteristics and host range, the barley and the wheat group isolated were identified asX. campestris pvs.hordei andcerealis, respectively.Aegilops sp.,Sclerochloa dura, andHeteranthelium sp. were, for the first time, shown to be hosts ofX. c. pv.cerealis.