Commercial Barley Cultivars Research Articles

Microsatellite-based diversity analysis and the development of core-set germplasm in Pakistani barley lines.

Illustrating the population structure and genetic diversity in selected germplasm resources (after three year multi locations trials) plays a key role which directly utilize the selection of lines in a population for accumulative trait breeding in crops. In order to further understand, the structure of population and genetic variability, we explored 100 selected lines, cultivated for three consecutive years (2016-2019) in swat, University of Malakand, Khyber Pakhtunkhwa Pakistan and Provinces of China (Chongqing and Beijing) with 33 mapped SSR markers. The integrated population structure analysis in a core of hundred germplasm with Pakistani origin with three approved commercial barley cultivars have strong stratification that allowed their division into four major subpopulations (i.e. PI, PII, PIII and PIV) and an admixture subpopulation, with 52, 9, 15 and 27 germplasm respectively. A total of 133 alleles were identified with mean value of 0.80 Polymorphic information content. The number of alleles detected by the system varied from two alleles amplified to as six with an average of 4.03 per SSR marker pair. The gene diversity ranged from 0.56 to 0.98 with an average of 0.82 in selected germplasm resources. Based on the SSR data, the 100 selected germplasm with three cultivars were classified into four main phylogenetic Linages (LI, LII, LIII and LIV) which corresponded to the phylogenic grouping in genotypes. We assembled a core set of 20 barley genotypes (~1/5 of original population size) to sustain sufficient mapping of SSR marker with Phenotype, in which we proposed four SSR markers, Bmac0040, Bmac0134, Bmag0125 and Bmag0211 for malt gene and marker (Bmac0399) for tolerance to salinity gene, which will be applicable for marker assisted breeding in barley gene resources.

Identification of a candidate dwarfing gene in Pallas, the first commercial barley cultivar generated through mutational breeding.

Many induced mutants are available in barley (Hordeum vulgare L.). One of the largest groups of induced mutants is the Erectoides (ert) mutants, which is characterized by a compact and upright spike and a shortened culm. One isolated mutant, ert-k.32, generated by X-ray treatment and registered in 1958 under the named "Pallas", was the first ever induced barley mutant to be released on the market. Its value was improved culm strength and enhanced lodging resistance. In this study, we aimed to identify the casual gene of the ert-k.32 mutant by whole genome sequencing of allelic ert-k mutants. The suggested Ert-k candidate gene, HORVU.MOREX.r3.6HG0574880, is located in the centromeric region of chromosome 6H. The gene product is an alpha/beta hydrolase with a catalytic triad in the active site composed of Ser-167, His-261 and Asp-232. In comparison to proteins derived from the Arabidopsis genome, ErtK is most similar to a thioesterase with de-S-acylation activity. This suggests that ErtK catalyzes post-translational modifications by removing fatty acids that are covalently attached to cysteine residues of target proteins involved in regulation of plant architecture and important commercial traits such as culm stability and lodging resistance.

Multi-locus genome-wide association studies reveal novel alleles for flowering time under vernalisation and extended photoperiod in a barley MAGIC population

Key messageKey genes controlling flowering and interactions of different photoperiod alleles with various environments were identified in a barley MAGIC population. A new candidate gene for vernalisation requirements was also detected.Optimal flowering time has a major impact on grain yield in crop species, including the globally important temperate cereal crop barley (Hordeum vulgare L.). Understanding the genetics of flowering is a key avenue to enhancing yield potential. Although bi-parental populations were used intensively to map genes controlling flowering, their lack of genetic diversity requires additional work to obtain desired gene combinations in the selected lines, especially when the two parental cultivars did not carry the genes. Multi-parent mapping populations, which use a combination of four or eight parental cultivars, have higher genetic and phenotypic diversity and can provide novel genetic combinations that cannot be achieved using bi-parental populations. This study uses a Multi-parent advanced generation intercross (MAGIC) population from four commercial barley cultivars to identify genes controlling flowering time in different environmental conditions. Genome-wide association studies (GWAS) were performed using 5,112 high-quality markers from Diversity Arrays Technology sequencing (DArT-seq), and Kompetitive allele-specific polymerase chain reaction (KASP) genetic markers were developed. Phenotypic data were collected from fifteen different field trials for three consecutive years. Planting was conducted at various sowing times, and plants were grown with/without additional vernalisation and extended photoperiod treatments. This study detected fourteen stable regions associated with flowering time across multiple environments. GWAS combined with pangenome data highlighted the role of CEN gene in flowering and enabled the prediction of different CEN alleles from parental lines. As the founder lines of the multi-parental population are elite germplasm, the favourable alleles identified in this study are directly relevant to breeding, increasing the efficiency of subsequent breeding strategies and offering better grain yield and adaptation to growing conditions.

Evaluation of malt barley cultivars for resistance against leaf scald (Rhynchosporium secalis) (Oudem JJ. Davis) and for yield and yield traits in North Shewa, Central high lands of Ethiopia

The production of malt barley is threatened by barley leaf scald caused by the fungus (Rhynchosporium secalis) is among the major foliar diseases affecting the production of the crop. A field experiment was conducted to evaluate malt barley cultivars for resistance to scald disease under natural infection of the field in north Shewa, in two locations of Debre Berhan University research field and Keyiet farmer’s field during 2017/2018 main cropping season. Thirteen commercial malt barley cultivars were arranged in randomized complete block design (RCBD) with three replications. Cultivar Sabini, Grace, Bahati, HB-120 had significantly, the highest initial and final disease severity index while Cultivar Ibon, EH-1847, Miscal-21, and Traveler had significantly the lowest initial and final disease severity index values at both locations. Farmers in the study area are recommended to use those better performing cultivars like Ibon, EH-1847, Miscal-21, and other resistant and moderately resistant cultivars.

Evaluation of Barley Cultivars for Competitive Traits in Southern New South Wales.

The potential of multi-purpose barley (Hordeum vulgare L.) cultivars to suppress weeds while maintaining optimal yield and grain quality has been reported but not recently evaluated in replicated field trials performed under southern Australian field conditions. Therefore, to investigate this potential, aboveground competitive traits were assessed in nine genetically diverse commercial barley cultivars in 2015, 2016 and 2017, in two locations in the Riverina region of NSW in replicated field trials performed in the absence of pre-emergent herbicide treatment. Crop and weed establishment, early vigour, leaf area index, photosynthetically active radiation (PAR) and biomass were assessed at various crop growth stages, including early growth, vegetative, flowering, grain fill and harvest. Cultivar differences in crop and weed biomass accumulation at ~50, 100 and 150 days after planting were noted at both locations. Early barley biomass accumulation was inversely related to weed biomass in both locations and most years, suggesting strong (over 90%) potential for heritable competitive barley interference against weeds. The current study also observed a positive relationship between PAR light interception and crop biomass in all three years at both locations, suggesting that PAR light interception contributed positively to crop biomass accumulation by directly increasing photosynthesis (50–70%) and growth or indirectly influencing weed biomass accumulation (10–15%) and weed interference (50–75). Partial least squares modelling was performed with 2015 and 2016 datasets to assess the interactions between crop developmental traits and weed suppression. Cultivars exhibiting enhanced early vigour and PAR light interception were generally more weed suppressive under optimal higher soil moisture conditions. Our results indicate that the choice of barley cultivar has a significant impact on weed establishment, fecundity and seedbank dynamics. The use of competitive barley genotypes is, thus, a cost-effective strategy to reduce weed seedbank numbers over time and may reduce potential herbicide use.

Association analysis of physiological traits in spring barley (Hordeum vulgare L.) under water-deficit conditions.

In the present study, 148 commercial barley cultivars were assessed by 14 AFLP primer combinations and 32 SSRs primer pairs. Population structure, linkage disequilibrium, and genomic regions associated with physiological traits under drought stress were investigated. The phenotypic results showed a high level of diversity between studied cultivars. The studied barley cultivars were divided into two subgroups. Linkage disequilibrium analysis revealed that r 2 values among all possible marker pairs have an average value of 0.0178. The mixed linear model procedure showed that totally, 207 loci had a significant association with investigated traits. 120 QTLs out of 207 were detected for traits under normal conditions, and 90 QTLs were detected for traits under drought stress conditions. Identified QTLs after validation and transferring to SCAR markers in the case of AFLPs can be used to develop MAS strategies for barley breeding programs. Some common markers were identified for a particular trait or some traits across normal and drought stress conditions. These markers show low interaction with environmental conditions (stable markers); therefore, selection by them for a trait under normal conditions will improve the trait value under stress conditions, too.

Development of a precise thermal time model for grain filling in barley: A critical assessment of base temperature estimation methods from field-collected data

Precise phenology modelling of grain filling is essential to understand how the environment explored by barley crops in the field affects malting quality. Grain-filling duration is controlled by temperature; hence thermal time models are widely used for describing grain development. Although a precise base temperature is essential for the accuracy of thermal time models, estimations of this parameter for barley grain filling are scarce in the literature; moreover, the methods employed for its determination seldom establish clearly whether grain filling is being treated as a development or as a growth phenomenon. Even worse, the base temperature during grain filling is usually arbitrarily set to zero. In this work we tested five different methods to estimate the thermal time requirement for completing grain filling in four commercial barley cultivars and the base temperature above which temperature must be accumulated for its calculation, using field-collected data. The crops were sown in a wide range of different dates during three consecutive years and grown under two contrasting nitrogen availabilities. All the estimation methods performed relatively well. Developmental base temperature was close to 8 °C for all cultivars, although genotypic differences were noted. Optimum temperatures for grain filling are reported for three of the four cultivars; however, including this parameter in the models only slightly improved the predictions in one out of three cultivars. The effect of nitrogen availability was negligible and inconsistent across cultivars and environments thus indicating that the models developed can be applied in a wide range of nutritional situations. A broad application model, with a base temperature of 8.4 °C and a thermal time requirement for completing grain filling of 352 °Cd, is reported for barley grain development. All the models were validated against independent data. These models can be used by researchers aiming to unscramble the effects of environment explored by the mother plant on grain malting quality. Further applications include predicting the timing of physiological maturity, and with it, harvest time.

Evaluation of Diverse Barley Cultivars and Landraces for Contents of Four Multifunctional Biomolecules with Nutraceutical Potential

Barley is long-identified as a functional food due to its content of micronutrients, β-glucans and vitamins. However, there is scant literature on a number of other nutritionally important biomolecules in the barley grain. This study determined the contents of four biomolecules, each with multiple known human and/or other animal health benefits, in the grains of 27 commercial barley cultivars and 7 landraces of barley from diverse countries of origin. These included the antioxidants, comprised of various vitamin E isomers and polyphenols, the osmoprotectant glycine betaine (GB) that protects cellular cytoplasm from osmotic shock, and the ‘plant stress hormone’ abscisic acid (ABA) which is endogenously expressed in humans and has multiple roles in physiology. All grains exhibited the presence of all biomolecules, suggesting they could potentially make some contribution to the health benefits of barley. The total vitamin E content varied between 19.20 - 54.56 μg/g DW, with α-tocotrienol being the major component (33.9 - 60.7%). The phenolics made up 3.21 - 9.73 mg gallic acid equivalent (GAE)/g DW, exceeding the amounts in the two major cereals, rice and wheat. GB ranged between 0.41-1.40 mg/g DW. The total vitamin E contents and GB typically exceeded those in corn. ABA ranged as 8.50 - 235.46 ng/g dry weight (DW), with the highest inter-variety variability. The data confirm barley to be an excellent source of these nutraceuticals, generally better than other major cereals. Our results thus offer more detailed insights into the potential of barley as a functional food and suggests the need to investigate in depth the health effects of this grain as well as the contribution of genetic and environmental factors.

Screening of barley breeding lines for resistance to common root rot disease through incidence and severity parameters

Cochliobolus sativus, the causal agent of common root rot (CRR), is a devastating fungal pathogen of barley that can cause significant yield losses worldwide. The development of resistant cultivars has proven difficult, therefore, in this work, CRR-resistant barley germplasm was developed by crossing three resistant-by-susceptible cultivars currently used in Europe and West Asia. Following greenhouse evaluations of 150 doubled haploid lines derived from these crosses, 40 lines were evaluated under artificial infection conditions using incidence and severity parameters during two consecutive seasons. Data showed significant differences among barley lines with a continuum of resistance levels ranging from highly susceptible to resistant which were consistent in both seasons. However, five promising lines had slightly lower CRR disease than the others. Additionally, significant differences (P <0.05) in mean incidence and severity values were found among lines, with values being consistently higher in the susceptible ones. However, CRR severity increased linearly as incidence increased in both seasons. All together, the present study suggests that, the newly identified resistance lines can serve as potential donors for ongoing CRR resistance breeding program to generate high-yielding commercial barley cultivars, and that the positive correlation between CRR parameters I and S may be beneficial for many types of studies on this disease.

Improving pedigree selection in applied breeding of barley populations

The objectives of this study were (a) to compare the effectiveness of the two methods of pedigree selection in barley: the ear-to-row classical pedigree method and the honeycomb method and (b) the evaluation of the selection criteria of the honeycomb methodology. Five F12 lines developed by classical pedigree method were used as checks in order to compare seven lines developed by honeycomb methodology. Five honeycomb pedigree lines were selected by PYI basic selection criterion of honeycomb methodology and two more (rejected by PYI) were selected by YC, a new criterion proposed for improving selection of high yielding plants in honeycomb design. Also, the original local population from which all these lines were derived and two commercial barley cultivars were used as the basic checks. All genotypes selected by classical and honeycomb pedigree method out yielded the original local population. Many of them reached or out yielded the commercial cultivars used as checks and thus both classical and honeycomb pedigree methods were able to promote some homozygous genotypes in order to be used as new cultivars. Yield performance of progeny lines selected by classical pedigree method was better than honeycomb’s. Only when YC was used as selection criterion honeycomb pedigree lines showed high yielding performance. Comparing PYI and YC selection criteria, it seems that the second is better for promoting high yielding and stable lines for next generations to be used as future new cultivars. Grain yield and bulk density are safer traits than 1000-kernel weight, for efficient selection that ensures high and stable yields.

A fitness cost resulting from Hamiltonella defensa infection is associated with altered probing and feeding behaviour in Rhopalosiphum padi.

Many herbivorous arthropods, including aphids, frequently associate with facultative endosymbiotic bacteria, which influence arthropod physiology and fitness. In aphids, endosymbionts can increase resistance against natural enemies, enhance aphid virulence and alter aphid fitness. Here, we used the electrical penetration graph technique to uncover physiological processes at the insect-plant interface affected by endosymbiont infection. We monitored the feeding and probing behaviour of four independent clonal lines of the cereal-feeding aphid Rhopalosiphum padi derived from the same multilocus genotype containing differential infection (+/-) with a common facultative endosymbiont, Hamiltonella defensa Aphid feeding was examined on a partially resistant wild relative of barley known to impair aphid fitness and a susceptible commercial barley cultivar. Compared with uninfected aphids, endosymbiont-infected aphids on both plant species exhibited a twofold increase in the number of plant cell punctures, a 50% reduction in the duration of each cellular puncture and a twofold higher probability of achieving sustained phloem ingestion. Feeding behaviour was also altered by host plant identity: endosymbiont-infected aphids spent less time probing plant tissue, required twice as many probes to reach the phloem and showed a 44% reduction in phloem ingestion when feeding on the wild barley relative compared with the susceptible commercial cultivar. Reduced feeding success could explain the 22% reduction in growth of H. defensa-infected aphids measured on the wild barley relative. This study provides the first demonstration of mechanisms at the aphid-plant interface contributing to physiological effects of endosymbiont infection on aphid fitness, through altered feeding processes on different quality host plants.

СКРИНИНГ ОБРАЗЦОВ МЕСТНЫХ ЯЧМЕНЕЙ НА ЧУВСТВИТЕЛЬНОСТЬ К ФОТОПЕРИОДУ

Background. Earliness of barley is an important trait for increasing the yield of this crop, especially in regions where abiotic factors are determinant. This work is dedicated to the identification of the eam8 gene in local barley accessions from the VIR collection. It would be possible to find sources of weak sensitivity to photoperiod to be used in breeding practice. Materials and methods . In Pushkin and Pavlovsk Laboratories of the N. I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR, St. Petersburg), 1460 local barley accessions from 26 countries with a short photoperiod of vegetation were studied. These countries are included in five centers of barley diversity: the Abyssinian, the Near East, the Mediterranean, the Central Asian, and the New World. The experiments were performed in the THERMO 818 (3751) climate chamber. Barley seeds were planted in cuvettes with moistened cotton wool. After the emergence of shoots, they were placed in the climate chamber where the plants remained until the stage of the second leaf with the 10-hour photoperiod and the temperature regime of a low daytime (+8°C) and high nighttime (+25°C) temperatures. Yellow color of a plantlet was the marker for the expression of the eam8 gene. Two varieties were used as references: 'Mari Svalofs' (k-19354; var. nutans Schubl.; Genotype eam8eam8) insensitive to photoperiod, and 'Belogorsky' (k-22089; var. pallidum Ser., var. ricotense Regel; Genotype Eam8Eam8) responding to a short day. Results and conclusions . Phenotypic screening of barley samples from 26 countries with a short photoperiod resulted in identification of 1379 forms with the Eam8Eam8 genotype (sensitive to a short day), 44 accessions with the eam8eam8 genotype (insensitive to a short photoperiod), and 37 heterogeneous accessions. Local barleys from Dagestan demonstrated the highest occurrence of forms with the eam8 gene (15.9%). The Near East and Central Asian centers of barley diversity were notable for the occurrence of local accessions with the recessive allele of the Eam8 gene. Accessions with the eam8eam8 genotype and heterogeneous forms can serve as sources of earliness in regions with short-light days. In order to include such sources in commercial barley cultivar breeding programs, they should be searched for in countries with a mountainous landscape and a short photoperiod.

Evaluation of Host Reaction and Yield Performance of Malt Barley Cultivars to Net Blotch, Pyrenophora teres in Bale Highlands, Ethiopia

The host reaction and yield performance of malt barley cultivars to net blotch, Pyrenophora teres disease was tested under natural infection of field at Sinana Agricultural Research Center (SARC) in Maher seasons of 2015. This study was designed to 12 commercial malt barley cultivars under field condition in Randomized Complete Block Design (RCBD) with two replications. The significant differences in severity (%), Area Under the Disease Progress Curve (AUDPC), grain yield (kg/ha), TKW (gm) and Days to Heading (DH) among the malt barley cultivars were observed. The HB-52 (4-68%), HB-1533 (12-54%) and Miscal-21 (4-68%) were scored the lowest ranges of severity index (%), where as IBON-174/03 (639.5%), HB-52 (611.4%) and HB-1533 (593.4%) were recorded the lowest means of AUDPC. The superior yield responses were obtained from HB-52 (1636kg/ha), Taveller (1647.5kg/ha), Miscal-21 (1775.5kg/ha) and Bekoji-1 (1752kg/ha) as compared to other cultivars. The disease severity % was gradually higher as the plant ages from seedling to maturity in all cultivars were tested to net blotch disease. Phonotypical scoring of net blotch on malt barley cultivar with yield performances were in to four categories; the yielder cultivar in the presence of net blotch disease pressure (Traveller, Bekoj-1 and Grace), both disease resistance and yielder cultivar (HB-52, Miscal-21), only net blotch resistance cultivar (HB-1533, IBON-174.03) and Cultivars (Beka, Sabini, Bahati, Fire Gebs and HB-120) were also identified as susceptibility to net blotch at natural infection in field with none yield advantage.

Drought stress effects on the grain yield among different barley cultivars

We examined commercial barley cultivars in two sequential growing season by including irrigation and rainfed conditions under a randomized complete block experimental design. There were positive and significant correlations between the yeild and either of the indices including Mean productivity (MP), Stress Tolerance Index (STI), Geometric Mean Productivity (GMP), Harmonic Mean Productivity (HMP), and Mean Relative Performance (MRP) in both irrigated and drought conditions. The PC1 and PC2 justified 94.86 and 94.44% of total variation in the first year and second year, respectively. According to 3-dimensional diagram and based on STI, genotypes 2, 3, and 8 in the first year and gentypes 4, 3, 8, and 2 in the second year were clustered together in group A, and therefore, called the most tolerant cultivars to drought stress.

Genotypic variation in the ability of landraces and commercial cereal varieties to avoid manganese deficiency in soils with limited manganese availability: is there a role for root‐exuded phytases?

The marginal agricultural-systems of the Machair in the Western Isles of Scotland often have limited micronutrient availability because of alkaline soils. Traditional landraces of oats, barley and rye are thought to be better adapted to cope with the limited manganese (Mn) availability of these soils. When commercial cultivars are grown on the Machair, limited Mn-availability reduces crop yield and quality. We hypothesised that traditional cereal landraces selected on the Machair acquire Mn more effectively and that this could be linked to exudation of phytase from roots which would release Mn complexed with inositol phosphates. Growth and Mn-acquisition of five landraces and three commercial cultivars of barley and oats were determined in Machair soil. In addition, root phytase activities were assayed under Mn-starvation and sufficiency in hydroponics. In Machair soil, landraces had greater capacity for acquiring Mn and a greater ability to achieve maximum yield compared to the commercial cultivars. Under Mn-starvation, root phytase exudation was upregulated in all plants, suggesting that this trait might allow cereals to acquire more Mn when Mn-availability is limited. In the landraces, exuded phytase activity related positively to relative Mn-accumulation, whereas in the commercial cultivars this relationship was negative, suggesting that this trait may be secondary to an efficiency trait that has been lost from commercial germplasm by breeding. This research shows that cereal landraces possess traits that could be useful for improving the Mn-acquisition of commercial varieties. Exploiting the genetic diversity of landraces could improve the sustainability of agriculture on marginal calcareous lands globally.

Root Architecture Variation in Wheat and Barley Cultivars

Aims: We analyzed root architecture variation among heirloom and commercial cultivars of wheat and barley to improve our understanding of the quantitative variation present within small grain root architectures. We also compared lab-based root architecture measures with cultivar shoot:root ratios and field data. Study Design: This study had a completely randomized design (CRD) with five replications of 5 heirloom and 4 commercial genotypes. Place and Duration of Study: The study was conducted in Plant Science Laboratory, Faculty of Land and Food Systems, The University of British Columbia, Canada, during May-June, 2012. Methodology: Wheat and barley seeds were grown on specific germination paper in a controlled environment, and were assessed for root architecture parameters: total root length, surface area, average diameter, root volume, number of tips, and branching angle (WinRHIZO Pro 2009c, Regent Instruments Inc.). Fisher’s least significant differences were calculated in MSTAT-C to assess genotypic variation of these parameters. We also calculated shoot:root ratios. These root architecture results were compared to parameters measured in the field for these cultivars. Results: Differences between wheat genotypes were identified among the cultivars with heirloom cultivars developing relatively larger and deeper root systems compared to the Original Research Article American Journal of Experimental Agriculture, 4(7): 849-856, 2014 850 commercial cultivars (i.e., longer and thinner roots, more surface area, higher number of tips, and greater branching angle). Commercial wheat cultivars showed coarser roots (i.e., greater root diameters), more root volume, higher dry weight, and shoot to root ratios compared to the heirloom cultivars with cv. ‘Scarlet’ showing the highest values. Among barley cultivars, heirloom ‘Jet’ had the highest values for parameters (i.e., length, area, volume, and branching angle) and the lowest shoot:root ratio compared to the commercial cvs. ‘Oxbridge’ and ‘Camus’. The commercial wheat cv. ‘Scarlet’ showed a positive association between grain yield, under low input organic conditions, and root diameter whereas the heirloom barley cv. ‘Jet’ had positive associations between grain yield, root length and surface area. Conclusion: The root architectures of the heirloom wheat and barley cultivars indicate they may be better suited for low phosphorus and/or drought conditions, typical of low input or organic production. The root architectures of the commercial cultivars, on the other hand, were deemed more suitable for high input conditions. There exists a positive association between root length, surface and yield potential when heirloom wheat cultivars were grown under low input conditions. Longer and finer roots, and the lower shoot:root ratio in some heirloom cultivars further suggest breeding potential for improved nutrient uptake efficiency and drought tolerance in wheat and barley.

Changes in cytokinin form and concentration in developing kernels correspond with variation in yield among field-grown barley cultivars

The aim of the present study was to determine if relationships between cytokinin (CK) profiles and corresponding enzymatic regulation were consistent with differences in kernel yield among commercial barley (Hordeum vulgare L.) cultivars, differing in parameters relating to productivity and grown under agronomically-relevant field conditions. Quantification of the CKs at six distinct stages of kernel development by high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) revealed a significant increase in CKs, especially trans-zeatin (tZ), during the stage when grain filling occurs, with a greater CK concentration observed in the cultivar with the greatest number of kernels per spike, which was also the highest yielding cultivar. High levels of the cis-zeatin (cZ) CK form were observed at the first developmental stage, indicating a possible role in early embryo development and viability. Cytokinin oxidase (CKX; EC 1.5.99.12) activity was evaluated at each stage through a colorimetric assay, as the enzyme provides a primary mechanism for the irreversible degradation and, thus, regulation of CKs. However, no peaks in CKX activity were observed and no differences were detected at the particular stages examined. Isopentenyl transferase (IPT) gene expression was also examined and suggests that biosynthesis contributes to regulation of CK concentrations in developing barley kernels.

Evaluation of Heirloom and Commercial Cultivars of Small Grains under Low Input Organic Systems

A cultivar trial, including commercial and heirloom cultivars of major cereals and grain legumes was conducted in Vancouver, BC, under low input organic conditions. We assessed 19 wheat (6 commercial and 13 heirloom), 17 barley (8 commercial and 9 heirloom), 5 pea, 5 favabean, 5 kidneybean, 2 lentil, and 2 soyabean cultivars for plant performance metrics, and their potential in a small grain:legume intercropping system. Heirloom wheat cultivars showed notable response in a number of parameters including late maturity, taller plants, greatest number of spikes per m2, longest spike, highest number of seed per spike, greater seed weight to volume ratio, and resistance to stripe rust compared with commercial cultivars. For the heirloom-type, 6 of 14 wheat cultivars, (i.e., “Reward”, “Glenn”, “Cerebs”, “Red Bobs”, “Sounders” and “Black Bearded”) produced yields comparable to the commercial cultivars (i.e., nearly 5 t/h or higher). Also, heirloom cultivars typically contained higher protein levels most suitable for baking and blending purposes with “Einkorn” displaying the highest level (16.2%). Heirloom and commercial barley cultivars did not differ significantly with respect to plant height, spike length, and seed weight to volume ratio. However, a number of heirloom cultivars (e.g., “Jet”, “Dolma”, “Andie” and “Himalayan”) displayed greater responses on earliness, number of spikes per m2, grain yield, protein content and seed weight to volume ratio. Pea and lentil yielded lower than the national average under trial conditions. However, heirloom peas “Corgi”, “De Grace”, “Snowbird”, and “Golden” were earlier compared to the commercial cultivar “Reward”. All kidney bean cultivars yielded ~3 t/h with the highest yield from “Red Kidney” (3.8 t/h). Fava and soyabean appeared as promising crops as the cultivars produced good growth and yields. Neither lentil (“Crimson” and “Essex”) produced satisfactory responses though they had excellent vegetative growth and flowered. Therefore, significant variation was observed including several heirloom cultivars displayed great potential in terms of yield, protein content, and disease resistance and that specific cultivars were better suited for an intercropping system.

Generation of transgenic barley lines producing human lactoferrin using mutant alpha-tubulin gene as the selective marker

The biolistic transformation method was used for genetic improvement of three commercial cultivars of barley (Oksamytoviy, Vodogray, and Hetman). The plasmid pHLFTuBA containing target gene hLF encoding human lactoferrin under the control of the rice glutein B-1 promoter GluB-1 was used for transformation. The gene encoding mutant alfa-tubulin conferring resistance to trifluralin (dinitroaniline herbicide) was used as the selective marker. The screening of different trifluralin concentrations ranging from 0.1–30 μM was used for determination of selective concentration of the agent. Two transgenic barley lines of cultivars Oksamytoviy and Hetman’s callus line were selected after 2–3 months of cultivation on 10 μM of trifluralin. To confirm stable integration of the transformed gene, the PCR analysis of leafs from regenerated plant after their adaptation on the ground was carried out. The 734 bp fragment of the target gene was amplified from both regenerated plants.

Asexual Genetic Exchange in the Barley Pathogen Rhynchosporium secalis

ABSTRACT The causal agent of barley scald, Rhynchosporium secalis, is a haploid anamorphic ascomycete with no known sexual stage. Nevertheless, a high degree of genetic variation has been observed in fungal populations on commercial barley cultivars and parasexuality has been suggested to contribute to this variation. In order to test whether asexual genetic exchange can occur, isolates of R. secalis were transformed to hygromycin B resistance or phleomycin resistance. Mixtures of transformants were co-inoculated either on agar or in planta and screened for the occurrence of dual-antibiotic-resistant colonies. No dual-antibiotic-resistant colonies resulted from mixing transformants of different fungal isolates. In contrast, with transformants originating from the same fungal isolate, asexual exchange of markers was demonstrated on agar plates and in planta. This is the first definitive evidence of asexual genetic exchange in R. secalis.