Variation in Rate and Duration of Growth Among Spring Barley Cultivars1

Ten two-rowed spring barley cultivars (Hordeum vulgare L.) were evaluated for growth parameters, i.e. crop growth rate, crop growth duration, grain filling rate, grain filling duration, vegetative growth rate, vegetative growth duration, single caryopsis filling rate, single caryopsis filling duration. Field studies were conducted on a sandy loam at Hohenschulen, Northern Germany with three levels of nitrogen fertilization and three sowing rates in 1986 to 1988. Cultivar effects were observed for all growth parameters except for crop growth rate and vegetative growth rate. But only crop growth duration n and grain filling duration showed positive correlations with grain yield. No growth rate parameter was related to yield. Biomass was correlated to crop growth duration and not to crop growth rate, while average caryopsis weight was strongly related to caryopsis filling rate and only moderately to caryopsis filling duration. Comparing grain filling rate and duration to individual caryopsis filling rate and duration, only grain filling rate and duration appeared to be relevant to grain yield. Since genetic variability for crop growth rate was lacking in the spring barley material tested, further improvement of yield would only result from increase in harvest index and/or longer crop growth duration.     

Multivariate analysis of traits determining adaptation in cultivated barley

Thirty‐nine barley varieties of different origin, representing different growth types, were included in a series of experiments aimed at analysing the variability in vernalization response, photoperiod sensitivity and earliness per se and establishing the types of ecoclimatic adaptability using multivariate analysis. In the case of spring barley varieties there was no correlation between any of the three traits. For winter barleys, a negative correlation was found between photoperiod sensitivity and vernalization response and between photoperiod sensitivity and earliness per se. Vernalization response and earliness per se showed a positive correlation. Among the winter barley varieties large variations were apparent in photoperiod sensitivity, vernalization response and earliness per se, which resulted in a tremendous variation in flowering patterns and frost tolerance. Between the spring barley varieties only wider variations in photoperiod sensitivity were detected. Based on the cluster analysis, the 39 varieties could be separated into seven groups. The spring barley varieties were placed in two groups, and the winter barleys in five groups representing different adaptational types. Among these five groups two represented the two opposing extreme combinations of photoperiod sensitivity and vernalization response. The combination of large photoperiod sensitivity and no vernalization response resulted in better frost tolerance than did the combination of photoperiod insensitivity and large vernalization response.     

新疆不同刈割期对春性大麦干草产量和青贮品质影响的研究

为了探明春性大麦在新疆地区作为青贮饲料的最佳刈割时间,以垦啤麦13、P13-3和甘啤4号为研究对象,分析不同刈割期（抽穗期、灌浆期、灌浆10d和蜡熟期）干物质产量、营养品质和青贮品质。结果表明,随着刈割期的推迟,垦啤麦13和P13-3干物质含量和干草产量显著增加,P13-3蜡熟期干草产量显著高于其他时期,参试的3个品种（系）中P13-3在蜡熟期干草产量最大,达到14 731.46kg/hm ²。随着刈割期的推后,3个春性大麦品种（系）干草中粗蛋白和粗脂肪含量呈下降趋势,垦啤麦13和P13-3的中性洗涤纤维含量逐渐上升。随着刈割时间的推迟,大麦青贮后乳酸、乙酸和丁酸含量呈下降趋势,垦啤麦13和P13-3在灌浆10d后青贮其发酵品质显著高于抽穗期和灌浆期。因此,从产量和品质两方面综合考虑,新疆地区春性大麦最佳青贮刈割时间为灌浆10d。     

Direct and Correlated Responses to Four Cycles of Divergent Selection for Heading Date in Barley*

In order to investigate the direct and correlated responses to selection for heading date in barley, two F₂ populations were subjected to four cycles of divergent selection. For each cross, eight populations selected for earliness (from 1E to 4E) and for lateness, (from 1L to 4L) and four unselected populations (1, 2, 3 and 4 SSD) were obtained and than compared together with parental lines. Selection caused a change greater than one day/cycle in Doth directions, and the cumulative responses were -5.4 and -5,9 days in the direction of earliness, 7.7 and 7,1 days in the opposite direction. Such results suggest that in the two base populations the heading, date is under the control of a polygenic system with prevailing additive effects and a slight directional dominance toward earliness. Early populations showed a reduction of ear moisture and an increase of plant height, ear extrusion, kernel weight and harvest index, whereas late populations showed the opposite changes. Grain yield was linearly reduced by selection for lateness, whereas no substantial change was evidenced in the opposite direction, so that 4E significantly out-yielded 4L in both crosses.     

Comparison of Spring Barley Lines Produced by Single Seed Descent, Pedigree Inbreeding and Doubled Haploidy

Samples of inbred lines of Hordeum vulgare produced by pedigree inbreeding, doubled haploidy and single seed descent have been compared for a range of agronomic characters. Differences between the means of the in bred s produced by single seed descent and pedigree breeding were due to differing levels of inbreeding. The present study confirmed chat recombinant inbred families which out-perform the higher scoring parent may be produced by either method. Caution should, however, be exercised when simply inherited characters controlled by major genes are fixed in early generations. Differences between the doubled haploid and single seed descent samples for the character thousand grain weight were attributable to coupling linkages involving epistatic genes. The production and evaluation of random inbred lines should be considered as an alternative to pedigree methods of barley breeding.     

Powdery Mildew Resistance Genes in 127 Northwest European Spring Barley Varieties

One hundred and twenty-seven spring barley varieties grown in Denmark since 1979 were characterized for resistance genes using 30 powdery mildew isolates. The resistance genes are traced in the pedigrees to verify the results. Eleven named genes, 12 tentatively named genes/resistances and six unknown resistances were found. Resistance in many varieties was based on combinations of either known genes or of known and new factors. The following five new or relatively new resistance genes more or less effective against the present powdery mildew populations were detected: the ‘Mlo’ resistance conferred by the recessive mlo gene with the characteristic infection type 0/(4), ‘Ricardo’ and ‘Turkish’ sources having gene Mla3 in common and ‘Turkish’ with Ml(Tu2) in addition. In three varieties the new resistance Ml(IM9) was found in combination with different Mia alleles. Variety ‘Jarek’ has two new unidentified resistances.     

Nuclear Mutations Affecting Chloroplastic Pigments of Photoperiod-insensitive Barley

Three photoperiod-sensitive spring barley cultivars (Hordeum vulgare L.) and three independently derived, single-gene, nuclear mutants expressing photoperiod insensitivity and extremely early heading time under short daylengths were investigated for chloroplastic pigment variation in three environments using reverse-phase high-performance liquid chromatography (HPLC) to account for differences in laminae colour. In a greenhouse, non-stress environment and in a full sunlight, high-temperature stress environment, no systematic differences were observed among pigments of the mutant-parent pairs. However, under 12 h of daily light (600 μE m ²sec^?1) and stress temperatures (20/10°C, night/day) in a growth chamber, the three mutants appeared similar to each other in chlorotic appearance and laminae pigment contents, but differed from the three non -chlorotic parents, which were similar to each other. The mutants had less chlorophyll a and b, β-carotene, lutein, taraxanthin, violaxanthin, and neoxanthin but more zeaxanthin than their parents. When shaded, the mutants became less chlorotic. How phenotypic differences for heading time and perception of day-length might be related to altered chloroplast contents remains unclear. The single-gene mutants conferring photopenod insensitivity were more sensitive to photothermal stress than their photoperiod-sensitive counterparts and as a result, their zeaxanthin content increased but the level of other pigments decreased.     

Performance and Variability of Local Barley Landraces in Near-Eastern Environments

Homozygous lines from six Syrian and two Jordanian landrace populations were tested under highly productive growing conditions in Tel Hadia (1982/83), under drought stress in Breda (1983/84), and under dryland salinity stress in Hegla (1982/83/84) in Syria. Mean grain yield levels ranged between 260 kg/ha and 4850 kg/ha. Under drought and salinity stress, the majority of the landrace lines out-yielded the best cheeks significantly. In Tel Hadia the check cultivars mostly outyielded the landrace lines, but not always significantly. In all environments the harvest index of the landrace lines was near the optimum for barley. They expressed intermediate plant height and time to flowering, high lodging susceptibility under favorable growing conditions, high protein content, and a wide range of yield component combinations. In the stress environments highly significant genetic variation among the landrace lines was found. The heritabilities for gram yield were high in these trials. The correlations between performance under stress and under favorable growing conditions were poor. Therefore, the largest gains for variety improvement for the Syrian steppe area are expected from direct selection under stress conditions. Unique responses in proline accumulation and germination patterns in saline solution indicated specific adaptation in this material. These landraces, thus, are a useful source of breeding material, which also widens the genetic base of the present breeding program.     

Yield Formation and Plant Metabolism of Spring Barley in Response to Locally Injected Ammonium

This study was conducted to elucidate the crop physiological basis for yield differences frequently observed in experiments comparing top‐dressing of N fertilizers with injection of ammonium or ammonium/urea solutions into the soil. The effects of diammonium phosphate (NH₄‐N) injected at the two‐leaf stage, calcium nitrate (NO₃‐N) broadcasted and incorporated before sowing, and a control without N fertilization (‐N) were assessed from measurements of growth, N‐uptake and N‐partitioning, light interception, gas exchange, leaf anatomy and the activity of key enzymes of N‐metabolism. The experiment was performed with spring barley (Hordeum vulgare L.) grown in 80‐l containers in a vegetation hall in Braunschweig, Germany. The plants in the NH₄‐N treatment produced a 20 % higher grain yield than those in the NO₃‐N treatment. The grain yield superiority of the NH₄‐N plants was attributable to a higher number of ears per plant (+13 %) and more grains per ear (+6 %). The NH₄‐N plants exhibited lower concentrations of inorganic cations than plants supplied with NO₃‐N. In the NH₄‐N treatment, the light penetrated more deeply into the crop canopy and the NH₄‐N plants exhibited a higher leaf carbon exchange rate at the different leaf layers than the NO₃‐N plants. It is concluded that as opposed to predominantly nitrate nutrition, provision of a persistent source of ammonium enables plants to take advantage of the positive yield effect of mixed N nutrition.     

Genetic Variability for Grain Yield and Protein Content in Barley and Its Modification by Net Blotch

Protein content, yield and 1000-grain weight of healthy and net blotch-diseased plants were studied in a diallel cross programme concerning nine different varieties of barley (Hordeum vulgare L.). F₁ hybrids and their parents were grown in the field in two randomized block design experiments each with three replications (three inoculated and three non-inoculated plots). General and specific combining abilities were determined for yield, protein percentage, 1000 grain weight, protein yield, and non-protein yield. A high genetic variability for the traits studied was observed. Non-protein yield and 1000-grain weight decreased significantly in inoculated plants where protein yield was not affected. Significant general and specific combining abilities were observed for all traits. Values for general and specific combining abilities were, in some cases, significantly modified by net blotch of barley. This indicates that attention must be paid to the danger of drawing conclusions in quantitative genetics studies dealing with both diseased and healthy plants.     

Distorted Segregation for Mildew Resistance in Doubled Haploid Lines of Spring Barley

The mildew reactions of the second generation of doubled haploid (DH) plants, derived from anther culture of crosses among three spring barley lines carrying different Mla mildew resistance alleles and the cv. ‘Pallas’, were analyzed by using a set of three European and one Israeli mildew isolate. The results indicated, (1) a significant level of distortion segregation in favour of resistant DH genotypes, which was possibly due to linkage of mildew resistance genes on chromosome 5 with genes for plant regeneration and (2) various degrees of dominance for the different resistance genes studied as well as the possible action of modifier genes.     

Studies on Low Crossabilities Encountered with the Hordeum bulbosum Method for Haploid Production of Barley, Hordeum vulgare L.

Crosses were made between four spring barley (Hordeum vulgare L.) cultivars and five F₁, hybrids with one genotype of Hordeum bulbosum L. in two locations to investigate further previous low crossabilities which had been found in the barley cultivar ‘Apex’ with H. bulbosum. Data at all the main steps of the H. bulbosum technique were recorded and statistically analyzed. Significant differences between barley genotypes were demonstrated for all characters. It was confirmed that ‘Apex’ has poor crossability with H. bulbosum. Out of the three F₁ hybrids having ‘Apex’ as one parent, two exhibited low crossability similarly to ‘Apex’ but one showed significantly higher seed setting than ‘Apex’. The effect of the location was only significant on seed setting, while genotype X location interactions were significant on seed setting, seed quality and rate of haploid plants in relation 10 florets pollinated. Another problem which has influenced the success rate of the H. bulbosum method was found in the cultivar ‘Havilla’. Although seed setting and seed quality were high for this cultivar, embryo differentiation was low. However, this latter problem was found to influence less the overall success rate than poor crossability. Mahalanobis's distances were calculated and the dendrite of the shortest distances between barley genotypes was plotted.     

Epicuticular Wax of the First Leaves of Two Barley Cultivars Studied by Cryo Scanning Electron Microscopy

Chemical fixation and critical point drying of plant tissue prior to scanning electron microscopy often degrades the outermost layer of the specimen, i.e. the epicuticular wax. Knowledge of the unaltered wax, including its morphology, is important because the wax constitutes the interface between the plant and its surroundings. Having worked previously with barley leaves (anatomy, infection biology of pathogens), we found it of interest to examine and describe the wax morphology on barley leaves and to determine whether or not there were differences between cultivars. Hence, the morphology of the epicuticular wax on the first leaf of two spring barley cultivars has been studied by scanning electron microscopy following cryofixation.
The wax on both cultivars consists chiefly of scales with a small proportion of rods and granules. There is little variation in wax morphology over each leaf side, and only minor differences between the abaxial and adaxial sides of the same leaf. Distinct differences are, however, observed between the two cultivars, especially regarding the thickness and the shape of the wax scales. The wax bodies cover the entire surface of a leaf except for parts of trichomes and guard cells, and some scattered wax free areas.
The morphology and distribution of wax are discussed in relation to studies made on barley leaves using different techniques. Also, the implications of wax morphology for disease resistance are briefly discussed.     

Gene for Resistance to Barley Mild Mosaic Virus in German Winter Barley Located on Chromosome 3L

In order to identify the chromosome arm carrying a gene for resistance to barley mild mosaic virus (BaMMV) in German winter barley cultivars, a line trisomic for the long arm of chromosome 3 (telo-trisomic 3L) was crossed to the resistant cvs. ‘Sonate’ and ‘Ogra’. Results of tests for BaMMV reaction in the F2 indicate that the gene for resistance in German cultivars is located on the long arm of chromosome 3.     

The Effect of Sugars and Growth Regulators on Embryoid Formation and Plant Regeneration from Barley Anther Culture

The influence of carbon source and growth regulator composition in induction medium on anther culture response was investigated using spring barley genotypes. Anthers were cultured on BAC3, Ficoll-containing medium, supplemented with one of the following carbohydrates: sucrose, maltose, cellobiosc and melibiose (6 % w/v). The use of either maltose or cellobiose resulted in a significantly higher anther response, calli and/or embryoid production and green plant regeneration compared to the incubation of anthers on a medium containing sucrose. Contrary to these results, the replacement of sucrose by melibiose in BAO medium, drastically reduced the efficiency of anther culture. As an average for the three genotypes tested, the frequency of green plants per 100 anthers plated was 9- to 22-fold higher on medium supplemented with sucrose or cellobiose than on medium containing melibiose as a sole carbohydrate. Among the growth regulators tested, the combination of auxin NAA (2 mg/l) and cytokinin BAP (1 mg/1) performed much better than the employment of auxin 2,4-D combined either with zeatin riboside or BAP as cytokinins. The beneficial effect of medium supplemented with NAA and BAP was associated with better embryoid formation compared to the other growth regulator combinations tested. The hormone-free combination gave a similar anther response and production of calli as any medium supplemented with growth regulators, but the regeneration capacity of calli produced on hormone-free medium was much lower, resulting in the drastic reduction of the number of both total and green regenerants.     

Effects of loci determining photoperiod sensitivity (Ppd-H1) and vernalization response (Sh2) on agronomic traits in the 'Dicktoo'×'Morex' barley mapping population

The objectives of this research were to determine the individual and interaction effects of the Ppd-H1 and Sh2 loci on agronomic traits under short- and long-photoperiod regimes. Nineteen doubled haploid (DH) lines from the ‘Dicktoo’בMorex’ mapping population, which represented the four genotypes at the Ppd-H1 and Sh2 loci, were pheno-typed in controlled environment photoperiods. Both Ppd-H1 and Sh2 had significant effects on several agronomic traits, in addition to their role in determining first node appearance and flowering time. The magnitude of these effects depended on daylight. Under long-day conditions (18 h) Ppd-H1, and under short-day conditions (12 h) Sh2 was a significant determinant of most characters. The interactions between these two loci were significant for several characters, particularly for yield components, under both long- and short-photoperiod regimes. Under the long-day treatment, Ppd-H1 influenced plant height through the determination of node number. There was an epistatic association between the two loci for both 1000-kernel weight and tillering. The combination of photoperiod insensitivity and vernalization requirement caused a significant increase in tillering. This was paralleled by a decrease in 1000-kernel weight. Under the long-day treatment, neither Ppd-H1 nor Sh2 influenced plant yield. Under short-day conditions, the combination of photoperiod insensitivity and vernalization requirement had a pronounced negative effect on plant yield.     

The Effect of Carbohydrate Composition and Concentration on Anther Culture Response in Barley (Hordeum vulgare L.)

Culture medium composition is critical for the successful induction of microspore division in vitro. The present experiments have focused on a relatively neglected area of cell and tissue culture research, namely the carbohydrate component used in the medium. Three spring barley genotypes were cultured on a medium which was modified by replacing sucrose with the following carbohydrates (6 % w/v): maltose, fructose, malt extract, galactose and a glucose (3 % w/v)/fructose (3 % w/v) mixture. Both maltose and malt extract were superior to sucrose in their capacity to induce green plantlet differentiation from microspores. The concentrations of both sucrose and maltose were also varied. Overall the response of anthers on maltose based media was higher than on sucrose based media. Furthermore, a concentration of maltose m the range 6—12 % w/v produced a higher frequency of green plants than a low concentration (1—3 % w/v). The effect of maltose based media on germplasm of direct relevance to barley breeders was also tested. The cultivar ‘Blenheim’ was shown to be very responsive and this genetic factor was transmitted to the F₁ hybrid. The frequency of haploid to diploid regenerants was not consistent over genotypes, but in general there were more haploid than diploid regenerants. The implications of these results for barley breeding are discussed.     

大麦基因组GRAS基因家族的全基因组鉴定与表达分析

GRAS基因家族是一类仅存在于植物并广泛参与其生长发育调控的转录因子,根据其序列结构和系统发育树分化特征,GRAS转录因子包含PATI,DELLA,HAM,SCR,SHR等多个亚家族成员.本研究利用大麦最新的基因组数据库,采用生物信息学的方法筛选鉴定出41条GRAS基因序列,其中有34条序列具有完整的GRAS家族蛋白特...     

The influence of photoperiod on the Vrn-H2 locus (4H) which is a major determinant of plant development and reproductive fitness traits in a facultative × winter barley (Hordeum vulgare L.) mapping population

To determine the effect of Vrn‐H2 locus on plant developmental and agronomic traits, detailed controlled environment tests involving a factorial set of vernalization and photoperiod treatments were carried out using doubled haploid lines developed from a facultative (Vrn‐H2^?) × winter (Vrn‐H2⁺) barley cross. The allele phase at the Vrn‐H2 locus influenced heading date as well as the developmental and agronomic traits. The performance of Vrn‐H2⁺ lines was significantly influenced by vernalization: reproductive fitness traits showed significant decreases without vernalization. However, the effects of alleles at the Vrn‐H2 locus extended beyond simple satisfaction of the vernalization requirement. Vrn‐H2⁺ lines showed increased reproductive fitness compared with Vrn‐H2^? lines when vernalization was followed by a long photoperiod. The responses of the two Vrn‐H2 allele classes to photoperiod duration were quite different in terms of heading date, developmental and agronomic traits. These results suggest that alleles at the Vrn‐H2 locus – and/or tightly linked gene(s) – respond primarily to the exogenous signal of vernalization (temperature), but when the vernalization requirement has been fulfilled, they also respond to photoperiod duration.     

Effect of Nitrogen and Phosphorus Levels on Barley Cultivars Grown in Semi-arid Conditions

Most farmers in the rainfed parts of Jordan who use fertilizers use less than optimum rates of N and P because of the uncertainties associated with rainfall. Research results obtained by the national program indicated that the use of improved barley cultivars and fertilizers would result in substantial yield increases. The objective of the present investigation was to determine the optimum combination level of N and P for newly promising cultivars. The effect of 0–0, 5–10, 10–20 and 15–30 kg.ha⁻¹ of nitrogen (N) and phosphorus (P) levels on barley cultivas Rum, Giza, Fun, Harmel and Arta under rainfed conditions in the Mediterranean climate was studied during two cropping seasons, 1994-95 and 1995–96. Increased grain and straw yields, total N and P uptake and RUE were recorded with increasing N and P levels for almost all cultivars. Rum was significantly (P = 0.05) the highest grain and straw producer and highest RUE at the 10 N- and 20 P kg.ha⁻¹ level. The cultivar × fertility level (N–P) interactions were not significant for both grain and straw yields and for total N and P uptake.