Barley Breeding Research Articles

Resistance of barley cultivars and accessions to pathotypes of the spot blotch causative agent

Background. The spot blotch disease caused by the hemibiotrophic fungus Bipolaris sorokiniana has become a serious problem for barley. Utilization of resistant or tolerant barley cultivars ensures sustainable diversity conservation and environmentfriendly crop production. Thus, supplying barley breeders with sources of resistance to harmful diseases is an urgent task. Materials and methods. A set of 100 barley accessions, earlier selected for different levels of resistance to B. sorokiniana, served as the material for this study. Eleven isolates of B. sorokiniana of various geographic origin, belonging to 4 pathotypes, were used for testing. The resistance of barley seedlings was assessed under controlled laboratory conditions, and that of adult plants under artificial infection pressure in the field. Responses to B. sorokiniana were scored using the 0–9 rating scale.Results and conclusions. Barley genotypes with race-specific resistance to the spot blotch causative agent were identified. The percentage of barley genotypes resistant to five isolates of B. sorokiniana pathotype 1 averaged 24.2%; two isolates of pathotype 3, 29.5%; three isolates of pathotype 7, 18.3%; and one isolate of pathotype 0, 37%. Barley accessions manifesting resistance in their seedlings, but susceptible in the phase of milk-wax ripeness, and vice versa, with seedling susceptibility and adult resistance, were identified. Six (6) barley genotypes showed seedling and adult resistance to pathotype 1, nine (9) to pathotype 3, and two (2) to pathotype 7. No barley accessions resistant to all isolates of the pathogen were found.

The potential of phenomic selection for the joint Ethiopian malt barley breeding program

AbstractPhenomic selection is an alternative approach to genomic selection that uses near‐infrared spectra information to predict the performance of genotypes. This research assessed the effectiveness of phenomic selection in barley (Hordeum vulgare L.) using data from 21 trials carried out at Bekoji, Kofele, Holetta, Debre Markos, and Debre Berhane in Ethiopia from 2018 to 2021. Fivefold cross‐validation analysis showed robust predictability for traits, ranging from 0.5 to 0.8 for days to heading, days to maturity, plant height, 1000‐kernel weight, and grain yield. Days to heading and days to maturity showed similar correlation patterns across the ranges of the wavelengths. Days to heading and 1000‐kernel weight were positively and negatively correlated along the range of the wavelength above 1800 nm, respectively. Forward validation using an independent set of genotypes provided predictability above 0.3 for all traits. This result underscores the effectiveness of phenomic selection and its potential application in low‐budget, small‐scale breeding programs. The study affirmed the Ethiopian barley breeding program could implement phenomic selection as a routine selection tool without extra cost.

Genetic diversity of naked barley accessions from the VIR collection for resistance to powdery mildew in the North-West Region of the Russian Federation

BACKGROUND: Barley is an important grain crop characterized by adaptability to various growing conditions. In recent years close attention has been paid to groups of naked barley which compared to covered barley is more susceptible to the influence of pathogens, that decreases the yield and quality of grain. Powdery mildew is the most harmful diseases of barley (caused by the biotrophic fungus Blumeria graminis (DC.) Golovin ex Speer f. sp. hordei Marchal). The search for new promising sources of resistance to powdery mildew is necessary for barley breeding. AIM: The aim is studying the powdery mildew resistance of naked spring barley accessions from the world collection of VIR and identifying promising sources for economically valuable traits. MATERIALS AND METHODS: In field and laboratory conditions 271 of naked barley accessions of different ecological and geographical origin were studied for powdery mildew resistance and other economically valuable traits (lodging resistance, duration of the vegetative period, yield). The pathogen inoculum for laboratory work was represented by the north-western population of the pathogen. The resistance of barley samples was assessed in the field using the VIR point scale, in the laboratory using the E.B. Mains, S.M. Dietz point scale. The highly effective to powdery mildew resistance allele mlo11 was identified using PCR. RESULTS: The diversity of barley of different origins in resistance to powdery mildew is shown. 16 samples mainly from Europe, local forms from Ethiopia, Japan and India, were found to be resistant in field condition. According to the results of the assessment at the juvenile stage, 1 highly resistant sample k-31058 and 5 moderately resistant (k-20923, k-25801, k-27165, k-29911, k-30231) were identified. The naked forms k-20923 from Germany and k-29911 from Poland were resistant at all stages of plant development. The mlo11 allele was detected in the Arabische variety (k-20923) and heterogeneous pathogen resistance accessions k-20921, k-25793, k-27080, k-29440, k-29820. CONCLUSIONS: As a result of the work the sources of resistance to powdery mildew with a complex of economically valuable traits were identified, which can be involve in the breeding.

Genome-wide identification and expression analysis of the SPL gene family and its response to abiotic stress in barley (Hordeum vulgare L.)

BackgroundSquamosa promoter-binding protein-like (SPL) is a plant-specific transcription factor that is widely involved in the regulation of plant growth and development, including flower and grain development, stress responses, and secondary metabolite synthesis. However, this gene family has not been comprehensively evaluated in barley, the most adaptable cereal crop with a high nutritional value.ResultsIn this study, a total of 15 HvSPL genes were identified based on the Hordeum vulgare genome. These genes were named HvSPL1 to HvSPL15 based on the chromosomal distribution of the HvSPL genes and were divided into seven groups (I, II, III, V, VI, VII, and VIII) based on the phylogenetic tree analysis. Chromosomal localization revealed one pair of tandem duplicated genes and one pair of segmental duplicated genes. The HvSPL genes exhibited the highest collinearity with the monocotyledonous plant, Zea mays (27 pairs), followed by Oryza sativa (18 pairs), Sorghum bicolor (16 pairs), and Arabidopsis thaliana (3 pairs), and the fewest homologous genes with Solanum lycopersicum (1 pair). The distribution of the HvSPL genes in the evolutionary tree was relatively scattered, and HvSPL proteins tended to cluster with SPL proteins from Z. mays and O. sativa, indicating a close relationship between HvSPL and SPL proteins from monocotyledonous plants. Finally, the spatial and temporal expression patterns of the 14 HvSPL genes from different subfamilies were determined using quantitative real-time polymerase chain reaction (qRT-PCR). Based on the results, the HvSPL gene family exhibited tissue-specific expression and played a regulatory role in grain development and abiotic stress. HvSPL genes are highly expressed in various tissues during seed development. The expression levels of HvSPL genes under the six abiotic stress conditions indicated that many genes responded to stress, especially HvSPL8, which exhibited high expression under multiple stress conditions, thereby warranting further attention.ConclusionIn this study, 15 SPL gene family members were identified in the genome of Hordeum vulgare, and the phylogenetic relationships, gene structure, replication events, gene expression, and potential roles of these genes in millet development were studied. Our findings lay the foundation for exploring the HvSPL genes and performing molecular breeding of barley.

SSR-BASED ASSESSMENT OF GENETIC DIVERSITY IN BARLEY COLLECTION FROM THE STATE COMMISSION FOR VARIETY TESTING OF AGRICULTURAL CROPS OF KAZAKHSTAN

Barley (Hordeum vulgare L.) is a globally significant cereal crop with a substantial production footprint. As a versatile commodity, it serves as a primary resource for animal feed, malting, and human consumption. Genetic diversity among 49 barley accessions procured from the State Commission for Variety Testing of Agricultural Crops in Kazakhstan was assessed using a set of 21 SSR markers associated with various agronomic traits. The collection exhibited moderate genetic diversity, as indicated by a mean polymorphic information content (PIC) of 0.548 ± 0.153 and a mean Shannon's information index (I) of 0.980 ± 0.317, aligning with previously reported estimates of barley genetic variation in the World. STRUCTURE analysis identified three distinct population clusters (K = 3) using Bayesian clustering and DeltaK, which was confirmed by PCoA results. However, neighbor-joining tree analysis revealed a more detailed population structure with six distinct clusters, indicating substantial genetic diversity within the barley collection. Distinct phenotypic variations were observed among identified genetic clusters, implying a strong association between genetic diversity and agronomic traits, including plant height, kernel number per spike, and grain yield. Seven barley accessions (GSI_B_60, GSI_B_82, GSI_B_216, GSI_B_85, GSI_B_96, GSI_B_141, and GSI_B_208) forming a cluster NJ_tree_2 demonstrated the highest mean grain yield of 50.99 ± 2.95 g/ m2. This specific cluster and its constituent accessions exhibit promising potential for development into high-yielding cultivars or as a valuable source of beneficial alleles for barley breeding initiatives.

Evaluation of barley genotypes for drought adaptability: based on stress indices and comprehensive evaluation as criteria.

The prevalence of drought events worldwide emphasizes the importance of screening and cultivating drought-adapted crops. In this study, 206 germplasm resources were used as materials, dry weight as target trait, and two genotyping methods as criteria to evaluate drought adaptability at the seedling establishment stage. The results showed a significant decrease in average dry weight of the tested germplasm resources (from 746.90 mg to 285.40 mg) and rich variation in the responses of dry weight among each genotype to drought (CV=61.14%). In traditional evaluation method, drought resistance coefficient (DC), geometric mean productivity index (GMP), mean productivity index (MP), stress susceptibility index (SSI), stress tolerance index (STI), and tolerance index (TOL) also exhibited diversity in tested genotypes (CV>30%). However, these indices showed varying degrees of explanation for dry weight under stress and non-stress environments and failed to differentiate drought adaptability among genotypes clearly. In new evaluation method, four stress indices were developed to quantify barley seedling production and stability capacities. Compared to traditional stress indices, the stress production index (SI) explained dry weight more comprehensively under stress conditions (R2 = 0.98), while the ideal production index (II) explained dry weight better under non-stress conditions (R2 = 0.89). Furthermore, the potential index (PI) and elasticity index (EI) eliminated disparities in traditional stress indices and comprehensively clarified the contribution of elasticity and potential to production capacity under drought stress. Ultimately, through grading evaluation and cluster analysis, the tested germplasm resources were effectively categorized, and 11 genotypes were identified as suitable for cultivation in arid areas. Overall, the comprehensive evaluation method based on the newly developed stress indices surpasses the traditional method in screening drought adaptability of crops and serves as a vital tool for identifying high-stability and high-production capacities genotypes in various environments, which is expected to provide practical guidance for barley planting and breeding in arid areas.

Comparative Analyses of Green Plantlet Regeneration in Barley (Hordeum vulgare L.) Anther Culture

The efficient doubled haploid (DH) plant production methods play a key role in accelerating the breeding of new varieties and hybrids in cultivated plants. Consequently, DH plant production methods are continuously improving for barley (Hordeum vulgare L.) breeding and research programs. Two plant regeneration (FHGR and K4NB) and three rooting media (MSr, N6I and ½N6I + Ca) were compared with four F1 barley cross-combinations to clarify the effect of medium on the regeneration of green and albino plantlets and acclimatization. The plant regeneration efficiency was higher using K4NB medium (74.53 green plantlets/100 anthers and 30.85 albino/100 anthers) compared to FHGR (55.77 green plantlets/100anthers and 21.32 albino/100 anthers). The percentage of acclimatization was highest when the K4NB regeneration medium was combined with the MSr rooting medium. Altogether, 61.83% of the anther culture-derived plantlets of 8 cross-combinations acclimatized to the greenhouse conditions, and 1403 acclimatized plantlets were produced from the F1 cross-combinations. Haploid (22.52%), diploid (69.37%) and tetraploid (8.11%) plantlets were identified among the 111 tested green plantlets by flow cytometric analyses. The tetraploid lines can be explored to offer new scopes for future barley research and breeding directions. Nearly one thousand DH plants have been integrated into our barley breeding program.

Characterization of Improved Barley Germplasm under Desert Environments Using Agro-Morphological and SSR Markers

Barley is indeed a versatile cereal crop, valued for its uses in food, animal feed, and increasingly in biofuel production. As interest grows in developing new barley genotypes that are better adapted to diverse environmental conditions and production systems, integrating agro-morphological evaluations with molecular marker analyses in barley breeding programs is essential for developing new genotypes. It is necessary to explore the genetic diversity of those germplasm to predicate their responses to targeted environments and regions. The current study explored the phenotypic and genotypic relations among Saudi advanced germplasm to facilitate the development of superior barley cultivars suitable for desert environments. Molecular microsatellites (SSR) markers revealed considerable wide genetic variation among Saudi germplasm and checks. Population structure analyses revealed four main groups. Those groups were validated using similarity analyses and coefficients. As well, principal components analysis (PCA) and heat map analyses separated the studied genotypes into four main groups. The improved Saudi germplasm, selected from the barley breeding program, revealed considerably wide genetic and phenotypic diversities, indicating the feasibility of selection to improve for semi-arid conditions. The improved line KSU-BR-C/G-2 had the highest grain yield and harvest index in the first season. Rihana/Lignee was followed by the KSU-BR-C/G-2 genotype, with a grain yield averaging 6734.07 (kg ha−1), in the first season. KSU-BR-88-29-10 yielded 20,000 kg ha−1 for biomass yield. In the second year, KSU-BR-30-7 had the highest biomass yield, with 27,037.04 kg ha−1.

Results of estimating promising winter barley varieties and lines

The current paper has presented the results of an analysis of promising winter barley lines and varieties developed by the FSBSI “Agricultural Research Center “Donskoy” to select valuable genotypes for breeding programs. The basis for the analysis of the studied samples was the methodology for a comprehensive estimation of breeding results, developed by the researchers from the FSBSI “ARC “Donskoy” and the FSBEI HE DSTU. The study was conducted at the FSBSI “Agricultural Research Center “Donskoy” in 2021–2023. Sowing was carried out in 6-fold repetition, the local variety ‘Timofey’ was taken as a standard. There have been analyzed 14 economically valuable traits, identified as the most significant according to the methodology for a comprehensive estimation of barley breeding identifiers. The purpose of the current study was to conduct a comparative estimation of breeding winter barley lines according to the most significant traits for the selection of promising samples. The studied varieties and lines were ranked according to a set of traits and properties into three groups, such as promising, not very promising, and unpromising. The promising group included the new varieties ‘Step’ and ‘Alabai’, sent to the State study in 2, 5, 6 and 8 regions of the Russian Federation in 2022 and 2023, respectively, as well as the lines ‘Parallelum 2015’, ‘Parallelum 2136’, ‘Pallidum 2100’ and ‘Bezosty 2074’, characterized by high indicators of a complex of basic economically valuable characteristics and properties. These samples are being planned to send to the State Commission of the Russian Federation for Testing and Protection of Breeding Achievements.

Novel QTL Hotspots for Barley Flowering Time, Plant Architecture, and Grain Yield

Barley (Hordeum vulgare L.) is one of the oldest cultivated grains and remains a significant crop globally. Barley breeders focus on developing high-yield cultivars resistant to biotic and abiotic stresses. Barley’s flowering time, regulated genetically and by environmental stimuli, significantly impacts all of its agronomic traits, including the grain yield and plant architecture. This study aimed to detect the quantitative trait loci (QTLs) affecting these traits in 273 two-row spring barley accessions from the USA, Kazakhstan, Europe, and the Middle East across two regions of Kazakhstan, evaluating their impact on grain yield. Genotypic data were obtained from 26,529 segregating single-nucleotide polymorphisms (SNPs), and field trial data for 273 accessions, which were obtained for six traits (heading time, maturity time, vegetation period, plant height, peduncle length, and grain yield) in two regions of Kazakhstan over three growth years. As a result of a genome-wide association study (GWAS), 95 QTLs were identified for 6 agronomic traits, including 58 QTLs linked with candidate genes and/or QTLs. The remaining 37 QTLs were putatively novel, with 13 of them forming 3 QTL hotspots on chromosomes 1H (5 QTLs in the interval of 13.4–41.4 Mbp), 3H (4 QTLs in 608.6–624.9 Mbp), and 6H (4 QTLs in 553.8–572.8 Mbp). These hotspots were pleiotropic, and targeting these regions would allow breeders to enhance multiple yield-associated traits.

Genome wide association study of seedling and adult plant leaf rust resistance in two subsets of barley genetic resources

Leaf rust (LR) caused by Puccinia hordei is a serious disease of barley worldwide, causing significant yield losses and reduced grain quality. Discovery and incorporation of new sources of resistance from gene bank accessions into barley breeding programs is essential for the development of leaf rust resistant varieties. To identify Quantitative Trait Loci (QTL) conferring LR resistance in the two barley subsets, the Generation Challenge Program (GCP) reference set of 142 accessions and the leaf rust subset constructed using the Focused Identification of Germplasm Strategy (FIGS) of 76 barley accessions, were genotyped to conduct a genome-wide association study (GWAS). The results revealed a total of 59 QTL in the 218 accessions phenotyped against barley leaf rust at the seedling stage using two P. hordei isolates (ISO-SAT and ISO-MRC), and at the adult plant stage in four environments in Morocco. Out of these 59 QTL, 10 QTL were associated with the seedling resistance (SR) and 49 QTL were associated with the adult plant resistance (APR). Four QTL showed stable effects in at least two environments for APR, whereas two common QTL associated with SR and APR were detected on chromosomes 2H and 7H. Furthermore, 39 QTL identified in this study were potentially novel. Interestingly, the sequences of 27 SNP markers encoded the candidate genes (CGs) with predicted protein functions in plant disease resistance. These results will provide new perspectives on the diversity of leaf rust resistance loci for fine mapping, isolation of resistance genes, and for marker-assisted selection for the LR resistance in barley breeding programs worldwide.

A Quantitative Trait Locus with a Major Effect on Root-Lesion Nematode Resistance in Barley.

Although the root-lesion nematode Pratylenchus thornei is known to affect barley (Hordeum vulgare L.), there have been no reports on the genetic control of P. thornei resistance in barley. In this research, P. thornei resistance was assessed for a panel of 46 barley mapping parents and for two mapping populations (Arapiles/Franklin and Denar/Baudin). With both populations, a highly significant quantitative trait locus (QTL) was mapped at the same position on the long arm of chromosome 7H. Single-nucleotide polymorphisms (SNPs) in this region were anchored to an RGT Planet pan-genome assembly and assayed on the mapping parents and other barley varieties. The results indicate that Arapiles, Denar, RGT Planet and several other varieties likely have the same resistance gene on chromosome 7H. Marker assays reported here could be used to select for P. thornei resistance in barley breeding. Analysis of existing barley pan-genomic and pan-transcriptomic data provided a list of candidate genes along with information on the expression and differential expression of some of those genes in barley root tissue. Further research is required to identify a specific barley gene that affects root-lesion nematode resistance.

QTL Analysis of β-Glucan Content and Other Grain Traits in a Recombinant Population of Spring Barley.

Barley with high grain β-glucan content is valuable for functional foods. The identification of loci for high β-glucan content is, thus, of great importance for barley breeding. Segregation mapping for the content in β-glucan and other barley grain components (starch, protein, lipid, ash, phosphorous, calcium, sodium) was performed using the progeny of the cross between Glacier AC38, a mutant with high amylose, and CDC Fibar, a high β-glucan waxy cultivar. The offspring of this cross showed transgressive segregation for β-glucan content. Linkage analysis based on single-nucleotide polymorphism (SNP) molecular markers was used for the genotyping of the parents and recombinant inbred lines (RILs). Two Quantitative Trait Loci (QTL) for β-glucan content and several QTL for other grain components were found. The former ones, located on chromosomes 1H and 7H, explained 27.9% and 27.4% of the phenotypic variance, respectively. Glacier AC38 provided the allele for high β-glucan content at the QTL on chromosome 1H, whereas CDC Fibar contributed the allele at the QTL on chromosome 7H. Their recombination resulted in a novel haplotype with higher β-glucan content, up to 18.4%. Candidate genes are proposed for these two QTL: HvCslF9, involved in β-glucan biosynthesis, for the QTL on chromosome 1H; Horvu_PLANET_7H01G069300, a gene encoding an ATP-Binding Cassette (ABC) transporter, for the QTL on chromosome 7H.

Genome-wide screening of meta-QTL and candidate genes controlling yield and yield-related traits in barley (Hordeum vulgare L.).

Increasing yield is an important goal of barley breeding. In this study, 54 papers published from 2001-2022 on QTL mapping for yield and yield-related traits in barley were collected, which contained 1080 QTLs mapped to the barley high-density consensus map for QTL meta-analysis. These initial QTLs were integrated into 85 meta-QTLs (MQTL) with a mean confidence interval (CI) of 2.76 cM, which was 7.86-fold narrower than the CI of the initial QTL. Among these 85 MQTLs, 68 MQTLs were validated in GWAS studies, and 25 breeder's MQTLs were screened from them. Seventeen barley orthologs of yield-related genes in rice and maize were identified within the hcMQTL region based on comparative genomics strategy and were presumed to be reliable candidates for controlling yield-related traits. The results of this study provide useful information for molecular marker-assisted breeding and candidate gene mining of yield-related traits in barley.

Herbage Quality of Eight Native Hordeum Ecotypes Collected From Natural Grassland & Pasture Ecology of Southeastern Anatolia

In this study, plant samples of eight different ecotypes of three distinct species of the genus Hordeum were collected at the anthesis stage of the plants in the 2023 spring in Southeastern Anatolia's natural grassland and pasture ecology. The quality analyses of the herbage samples of Hordeum bulbosum, H. murinum, and H. spontaneum ecotypes collected from five different locations (Karacadag-I, Batman-1, Diyarbakır-6, Diyarbakır-8, and Diyarbakır-13) were determined by NIRS analyzer. Crude protein (CP), dry matter (DM), acid detergent insoluble fiber (ADF), neutral detergent insoluble fiber (NDF), acid detergent insoluble protein (ADP), Ca, K, Mg, P, Ca/P, K/(Ca+Mg), digestible dry matter (DDM), dry matter intake (DMI) and relative feed values (RFV) were determined. The values were determined between 8.2-23.4% for CP; 92.1-93.4% for DM; 19.3-36.2% for ADF; 26.2-71.9% for NDF; 0.16-0.71% for ADP; 60.7-73.9% for DDM; 1.67-4.58% for DMI; 78.6-262.8 for RFV; 0.30-0.42% for P; 1.72-2.84% for K; 0.12-1.62% for Ca; 0.17-0.30% for Mg; 0.33-3.84 for Ca/P; 2.76-4.77 for K/(Ca+Mg). In conclusion, the CP, ADF, NDF, DMI, RFV, and Ca/P values were found very variable in collected ecotypes and can be used for forage barley breeding purposes.

Characterizing stay-green in barley across diverse environments: unveiling novel haplotypes

Key messageThere is variation in stay-green within barley breeding germplasm, influenced by multiple haplotypes and environmental conditions. The positive genetic correlation between stay-green and yield across multiple environments highlights the potential as a future breeding target.Barley is considered one of the most naturally resilient crops making it an excellent candidate to dissect the genetics of drought adaptive component traits. Stay-green, is thought to contribute to drought adaptation, in which the photosynthetic machinery is maintained for a longer period post-anthesis increasing the photosynthetic duration of the plant. In other cereal crops, including wheat, stay-green has been linked to increased yield under water-limited conditions. Utilizing a panel of diverse barley breeding lines from a commercial breeding program we aimed to characterize stay-green in four environments across two years. Spatiotemporal modeling was used to accurately model senescence patterns from flowering to maturity characterizing the variation for stay-green in barley for the first time. Environmental effects were identified, and multi-environment trait analysis was performed for stay-green characteristics during grain filling. A consistently positive genetic correlation was found between yield and stay-green. Twenty-two chromosomal regions with large effect haplotypes were identified across and within environment types, with ten being identified in multiple environments. In silico stacking of multiple desirable haplotypes showed an opportunity to improve the stay-green phenotype through targeted breeding. This study is the first of its kind to model barley stay-green in a large breeding panel and has detected novel, stable and environment specific haplotypes. This provides a platform for breeders to develop Australian barley with custom senescence profiles for improved drought adaptation.

Systematic Analysis of Zinc Finger-Homeodomain Transcription Factors (ZF-HDs) in Barley (Hordeum vulgare L.).

Zinc finger-homeodomain transcription factors (ZF-HDs) are pivotal in regulating plant growth, development, and diverse stress responses. In this study, we found 8 ZF-HD genes in barley genome. Theses eight HvZF-HD genes were located on five chromosomes, and classified into ZHD and MIF subfamily. The collinearity, gene structure, conserved motif, and cis-elements of HvZF-HD genes were also analyzed. Real-time PCR results suggested that the expression of HvZF-HD4, HvZF-HD6, HvZF-HD7 and HvZF-HD8 were up-regulated after hormones (ABA, GA3 and MeJA) or PEG treatments, especially HvZF-HD6 was significantly induced. These results provide useful information of ZF-HD genes to future study aimed at barley breeding.

Registration of the “Woodies” multi–rust‐resistant barley germplasm

AbstractSelection for resistance to plant diseases is a continuous effort on the part of plant breeders. Sources of genetic resistance are often limited, despite considerable discovery efforts. Stem rust and stripe rust are two diseases of particular importance in barley (Hordeum vulgare L.) production. The present work aims to develop and deploy genotypes with resistance to these diseases that can be used in future breeding efforts. The Woodies, Woody‐1 (DH160733; Reg. no. GP‐218, PI 704479) and Woody‐2 (DH160754; Reg. no. GP‐219, PI 704480), are two doubled‐haploid genotypes produced via F1 anther culture named in honor of the late Lynn “Woody” Gallagher. These two‐row spring habit barley germplasm accessions were released by the Oregon Agricultural Experiment Station in 2023. These genotypes have demonstrated resistance to both stem and stripe rust at the seedling and adult plant stage in trials conducted between 2018 and 2023. The genetic basis of this resistance appears to be a novel quantitative trait locus conferring resistance to both diseases on chromosome 5H that is different from the known rpg4/Rpg5 complex for stem rust resistance found on the same chromosome. Seed can be requested from the Oregon State University Barley Breeding Program or from the NLGRP Germplasm repository.

Genome-wide association study on seed dormancy in barley

Abstract Seed dormancy is an important trait associated with pre-sprouting and malting quality in barley. Genome-wide association studies (GWASs) have been used to detect quantitative trait loci (QTLs) underlying complex traits in major crops. In the present study, we collected 295 barley (Hordeum vulgare L.) accessions from Australia, Europe, Canada and China. A total of 25,179 single nucleotide polymorphism (SNP)/diversity arrays technology sequence markers were used for population structure, linkage disequilibrium and GWAS analysis. Candidate genes within QTL regions were investigated, and their expression levels were analysed using RNAseq data. Five QTLs for seed dormancy were identified. One QTL was mapped on chromosome 1H, and one QTL was mapped on chromosome 4H, while three QTLs were located on chromosome 5H. This is the first report of a QTL on the short arm of chromosome 5H in barley. Molecular markers linked to the QTL can be used for marker-assisted selection in barley breeding programmes.

Evaluation of yield and stability of spring barley mutants of M5-M7 generations

Yield is an important indicator when creating new varieties of crops. Seeking high and stable yields is considered essential in barley breeding. The stability of the studied genotypes was analyzed using various statistical indicators, namely, bᵢ, S²dᵢ, Wi2, σ2i, CV. The experiment was conducted to evaluate yield and stability of barley mutants of M5-M7 generations by parametric statistics. The experiment involved 40 mutants of spring barley belonging to the two-row subsp. distichon L. and six-row subsp. vulgare obtained after mutagenic treatment with phosphemide in two concentrations. The research was carried out in 2020‒2022 on the experimental plot of Federal Horticultural Center for Breeding, Agrotechnology and Nursery (Moscow region, Russia). Phenotypic manifestation of the considered traits and yield varied depending on the year of the experiment. Mutants G3, G5, G7, G16, G19, G20, G22, G23, G24, G27, G29, G33, G34, G40 were characterized by a statistically significant excess of control samples on the weight of 1000 grains. The yield of the studied mutants obtained from the Zernogradsky 813 sample was noted in the range of 282.0– 317.9 g/m2, Dz02-129 had 137.2–201.5 g/m2, C.I.10995 had 90.9–282.7 g/m2, a high variability of this trait was observed with the coefficient of variation equal to 71.02 – 152.42%. The highest value of pair correlation of yield was registered with grain weight per plant (r=0.370) and weight of 1000 grains (r=0.371). Strong conjugation was found between bi and CV (r=0.659); S²di and Wi 2 (r=0.885), σ2i (r=0.885); σ2i and Wi 2 (r=1.000). In addition, a close correlation of yield was noted with bᵢ (r=0.459), S²di (r=0.462), Wi2 (r=0.470), σ2 (r=0.470). Mutants G4, G28, G29 were characterized by relatively stable yields. The complex of economic traits combined with high yield potential was possessed by two-row G1, G2, G40 and multi-row G16, G23 to be recommended for use in the breeding process for high productivity.