Ethiopian Barley Research Articles

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.

Four Ethiopian barley (H. Vulgare) varieties with a range of tolerance to salinity and water stress

Drought and salinity pose significant challenges to global agriculture by reducing crop yields. This study investigated the combined effects of drought and salt stress on the four malt barley (H. vulgare) strains, evaluating their resistance to different stress levels. Three sets of experiments used polyethylene glycol (PEG 6000) for drought stress (4%, 8%, and 12% w/v) and NaCl for salt stress (40 mM, 80 mM, and 120 mM). The control was made of distilled water. Barley strains with accession numbers (215460, 64,167, 16,805, and 202,642) exhibited varying degrees of tolerance. Notably, the Boreda strain (64,167) displayed strong resilience, while the Kosha strain (215460) showed weak tolerance. Germination percentages varied, with some non-combination stress conditions resembling controls. Overall, Boreda (64,167) emerged as a promising H. vulgare strain with potential for production despite dual stress conditions, showcasing its resilience to drought and salinity.

Genome wide association study of Ethiopian barley for terminal drought stress tolerance under field and climate chamber conditions

In order to detect markers for drought stress tolerance, field experiments in Ethiopia were conducted for three years at two naturally drought-prone locations and two optimum moisture locations using 239 Ethiopian barley landraces and 21 barley breeding lines. Furthermore, a climate chamber experiment applying drought stress at different water regimes (70% soil water capacity (WC) for control and 20% WC for drought stress conditions) after flowering was conducted for selected 196 accessions. Results revealed reduced grain biomass by 47% and 80% under field and climate chamber conditions, respectively, as well as significantly (p < 0.05) reduced days to maturity and plant height, in both experimental designs. Based on 10,644 SNP markers, GWAS was conducted to identify marker trait associations (MTA) for drought stress tolerance. For days to maturity, relative chlorophyll content, plant height, number of seeds per spike, thousand kernel weight, and harvest index under field and climate chamber drought stress treatments, 58 significant MTAs were identified. In total, 41.4% of the MTAs were located on chromosome 2H, of which one is very close to the Ppd-H1 flowering locus. These findings underpin the importance of this genome region for drought tolerance. Another MTA on chromosome 1H was detected for days to maturity under field drought stress treatment in the vicinity of the known flowering time ELF3 gene. Additionally, 13 and 3 Ethiopian landraces that tolerate severe and moderate drought stress in climate chamber and field experiments were identified, respectively, using drought indices. The results highlight the tolerance of Ethiopian landraces to different levels of drought stress as well as their potential to be considered in future barley improvement programs.

Phenotypic characterization and seed viability test in ex-situ conserved Ethiopian cultivated barley (Hordeum vulgare L.) landraces

BackgroundNowadays, most of the Ethiopian barley landraces had been lost from farmer’s field and exclusively found ex-situ conserved at the Ethiopian Biodiversity Institute (EBI). Those ex-situ conserved are generally believed to be representative of the original population and possess high genetic diversity and important unique genes that are useful for tackling the various biotic and abiotic stresses in the face of the current climate change. Thus, this research was aimed at testing the performance of 150 ex-situ conserved landraces that had been collected from Arsi and Bale highlands, Southeastern Ethiopia. The landraces were tested at multiple test locations over two years (2021 and 2022).ResultsAll the tested landraces showed a good germination rate regardless of their long storage duration. In addition, performance of all the qualitative traits revealed a varying frequency for each character state. For example, most of the accessions (51.3%) had six kernel row numbers (KRN). All the remaining accessions had two rows (28.7%) and irregular KRN with variable lateral florets (20%). Likewise, some of the quantitative traits considered showed a significant variation among the landraces. However, there observed a significant variation for all the interaction effects in some of the traits considered signifying the importance of considering environment effects while targeting genetic selection and improvement of ex-situ conserved germplasms. The phenotypic coefficients of variation (PCV) were considerably high to medium in most of the traits considered including seed yield per hectare (SYPH) but with no associated higher genotypic coefficients of variation (GCV). Moreover, all the traits showed a far greater phenotypic coefficient of variation (PCV) to that of genotypic coefficients of variation (GCV) once again suggesting the pronounced effect of environmental factors to the variation. This was far supported by the significantly higher absolute magnitudes in phenotypic correlation compared to their corresponding genotypic correlation in most of the traits. Low estimates of heritability and genetic advance observed in all the traits considered except seed yield per hectare indicate importance of the trait for selection in Ethiopian barley improvement programs. Clustering patterns of the accessions, in narrow sense, revealed the existence of low divergence among the samples.ConclusionEthiopian barley landraces are promising candidates for further yield improvement and conservation. However, further regular testing and screening should be conducted for the ex-situ conserved landraces because of the current erratic climate change. In addition, more robust molecular marker systems could be used to clearly reveal the extents of genetic diversity and to facilitate the breeding and conservation of Ethiopian barley landraces.

The association between hordein polypeptide banding and agronomic traits in partitioning genetic diversity in six-rowed Ethiopian barley lines (Hordeum vulgare L.)

BackgroundEvaluation of the extent of genetic variation within and between the populations of crop genetic resources are of paramount importance in any breeding program. An experiment aimed at assessing the extent of variation among barley lines and the degree of association between hordein polypeptide and agronomic traits was hence executed.MethodsField experiment was conducted in six environments between 2017–2019 involving 19 barley lines. Hordein bands were separated using vertical Sodium Dodecyl Sulphate Poly- acrylamide Gel Electrophoresis (SDS-PAGE).ResultsThe analysis of variance revealed significant variation among lines and wider range units were observed for the agronomic traits. The line (Acc# 16,811–6) was superior, producing the highest grain yield (2.97 ton ha−1) across environments, 3.6 ton ha−1 at Holleta, and 1.93 ton ha−1 at Chefedonsa. At Arsi Negelle a different line Acc# 17146–9 was the highest yielding (3.15ton ha−1). SDS-PAGE-based analysis of barley lines separated 12 hordein bands between C (four bands) and B (eight bands) subunits. Interestingly bands 52, 46a, and 46b were uniquely conserved in the four naked barley lines (Acc#16809–14,16956–11, 17240–3, 17244–19). A considerably high proportion of genetic diversity within the populations than among the populations could be a repercussion of high gene flow which substantiates the longstanding and dominant informal seed exchange system among the farmers. The significant positive association between grain yield and band 50 evocates the expression of this allele may code for higher grain yield. The negative association between days to maturity and band 52 perhaps stipulates earliness in barely lines upon the manifestation of the band. Band 52 and 60 appeared to be associated with more than one agronomic trait (days to maturity and thousand kernel weight; grain filling period and grain yield respectively) and could be the result of pleiotropic characteristics of the genes residing in these banding regions.ConclusionThe barley lines exhibited substantial variation for hordein protein and agronomic traits. However, imparted the need for the implementation of decentralized breeding as a consequence of genotype-by-environment interaction. Significant hordein polypeptide and agronomic traits association advocated the utilization of hordein as a protein marker and perhaps consider them in the parental line selection.

The genomic and bioclimatic characterization of Ethiopian barley (Hordeum vulgare L.) unveils challenges and opportunities to adapt to a changing climate.

The climate crisis is impacting agroecosystems and threatening food security of millions of smallholder farmers. Understanding the potential for current and future climatic adaptation of local crop agrobiodiversity may guide breeding efforts and support resilience of agriculture. Here, we combine a genomic and climatic characterization of a large collection of traditional barley varieties from Ethiopia, a staple for local smallholder farmers cropping in challenging environments. We find that the genomic diversity of barley landraces can be partially traced back to geographic and environmental diversity of the landscape. We employ a machine learning approach to model Ethiopian barley adaptation to current climate and to identify areas where its existing diversity may not be well adapted in future climate scenarios. We use this information to identify optimal trajectories of assisted migration compensating to detrimental effects of climate change, finding that Ethiopian barley diversity bears opportunities for adaptation to the climate crisis. We then characterize phenology traits in the collection in two common garden experiments in Ethiopia, using genome-wide association approaches to identify genomic loci associated with timing of flowering and maturity of the spike. We combine this information with genotype-environment associations finding that loci involved in flowering time may also explain environmental adaptation. Our data show that integrated genomic, climatic, and phenotypic characterizations of agrobiodiversity may provide breeding with actionable information to improve local adaptation in smallholder farming systems.

Morphological variations of qualitative traits of barley (Hordeum vulgare L.) accessions in Ethiopia

Ethiopian barley germplasm is a potential source of useful traits to fight the production challenges of barley farming and to enhance yield productivity in favorable and marginal environments. A study was carried out to assess the distribution and patterns of 17 qualitative trait variations among 85 Ethiopian barley accessions using an alpha lattice design with two replications. The Shannon-Weaver diversity (H′) index was used to estimate morphological diversity. Fifteen morphological traits of barley accessions originating from various regions of origins and altitude ranges were polymorphic. However, two traits including stem branching and lemma awn were monomorphic. The highest (0.94) overall mean of H′ was obtained for glume colour, kernel row and kernel shape. The estimated H′ ranged from 0.41 to 0.99 across regions, and 0.52 to 0.99 across altitude ranges with an overall mean of 0.76. The analysis of variance of H′ showed significant variation for most studied traits. Principal components analysis revealed that eight traits were the major loading on the first two principal components that describe 38.3% of the total morphological variance. Heat map analysis based on morphological traits of barley accessions was also grouped into three distinct clusters. Thus, the present finding confirmed that the Ethiopian barley accessions showed vast morphological variations across the region of origins and altitude ranges. Based on the result, further evaluation is ongoing to exploit specific gene variations through phenotyping and genotyping trait association.

The genetic diversity of Ethiopian barley genotypes in relation to their geographical origin.

Ethiopia is recognized as a center of diversity for barley, and its landraces are known for the distinct genetic features compared to other barley collections. The genetic diversity of Ethiopian barley likely results from the highly diverse topography, altitude, climate conditions, soil types, and farming systems. To get detailed information on the genetic diversity a panel of 260 accessions, comprising 239 landraces and 21 barley breeding lines, obtained from the Ethiopian biodiversity institute (EBI) and the national barley improvement program, respectively were studied for their genetic diversity using the 50k iSelect single nucleotide polymorphism (SNP) array. A total of 983 highly informative SNP markers were used for structure and diversity analysis. Three genetically distinct clusters were obtained from the structure analysis comprising 80, 71, and 109 accessions, respectively. Analysis of molecular variance (AMOVA) revealed the presence of higher genetic variation (89%) within the clusters than between the clusters (11%), with moderate genetic differentiation (PhiPT = 0.11) and five accessions were detected as first-generation migrants using Monte Carlo resampling methods. The Mantel test revealed that the genetic distance between accessions is poorly associated with their geographical distance. Despite the observed weak correlation between geographic distance and genetic differentiation, for some regions like Gonder, Jimma, Gamo-Gofa, Shewa, and Welo, more than 50% of the landraces derived from these regions are assigned to one of the three clusters.

Simulating the effect of climate change on barley yield in Ethiopia with the DSSAT‐CERES‐Barley model

AbstractClimate change is expected to have a major effect on crop production in sub‐Saharan Africa. Crop models can help to guide crop management under future climate. The objective of the study was to investigate the possible effects of climate change on Ethiopian barley (Hordeum vulgare L.) production using the Decision Support System for Agrotechnology Transfer (DSSAT)‐Crop Environment Resource Synthesis (CERES)‐Barley model. The study included field data of two barley cultivars (Traveller and EH‐1493) and four climate study areas in Ethiopia over 5 yr. Climate change scenarios were set up over 60 yr using representative concentration pathways (RCP; RCP4.5 and RCP8.5) and five global climate models (GCM). The model results indicated that the prediction of days to anthesis and maturity, as well as final grain yield, was highly accurate for cultivar Traveller with normalized RMSE (nRMSE) of 2, 1, and 12%, respectively, and for cultivar EH‐1493 with nRMSE of 2, 4, and 11%. A consistent increase in average temperature up to 5 °C and a mixed pattern of rainfall (‐61 to +86%) were projected. Yield simulations showed a potential reduction in yield up to 98% for cultivar Traveller and 63% for cultivar EH‐1493 in the future. Within a sensitivity analysis, different sowing dates, sowing densities, and fertilizer rates were tested as potential adaptation approaches to climate change. The negative effects of climate change could be mitigated by early sowing, with an increased sowing density of 25% and fertilizer rate of 50% more than what is recommended. Overall, the results indicated the ability of the CERES‐Barley model to evaluate climate change effects and adaptation options on rainfed barley production in Ethiopia.

Mineral contents of barley grains and its processed foods (kolo, porridge, bread and injera) consumed in Ethiopia

ABSTRACT. Barley (Hordeum vulgare L.) is one of the most widely cultivated stable food crops in the world. Barley grain samples were collected from four selected areas (Bahir Dar, Bure, Finote Selam and Debre Markos) of Ethiopia and four types of processed food (kolo, porridge, bread and injera) were prepared from it. The levels of essential and non-essential metals in barley grains and its processed food were determined by microwave plasma-atomic emission spectrometry after wet digestion with a mixture of HNO3 and HClO4 (5:1, v/v). The concentration (mg/kg dry weight) in the barley grains were in the ranges K (5482-6516), Mg (546-643), Ca (445-684), Mn (7.31-9.80), Fe (127-439), Cu (0.88-1.86), Zn (42.8-56.8), Pb (0.39-2.73), Cd (3.01-4.66). The concentrations of all the metals in the four types of processed barley foods showed variation among each other. The results indicate that Ethiopian barley grains and its processed foods are good source of essential metals.&#x0D; &#x0D; KEY WORDS: Barley, Hordeum vulgare L., Processed foods, Macro-minerals, Micro-minerals, Toxic metals&#x0D; &#x0D; Bull. Chem. Soc. Ethiop. 2021, 35(3), 471-484.&#x0D; DOI: https://dx.doi.org/10.4314/bcse.v35i3.1

Genetic diversity, population structure and relationship of Ethiopian barley (Hordeum vulgare L.) landraces as revealed by SSR markers

Evaluation and characterization of genetic resources maintained at both in situ and ex situ GenBanks have important implications for future utilization in association mapping studies, genetic selection, breeding and conservation activities. The main objective of this study was to evaluate the genetic diversity, population structure and relationship of 384 Ethiopian barley genotypes collected from different barley growing regions of Ethiopia using 49 simple sequence repeat (SSR) markers. Analysis of these 49 SSR markers amplified a total of 478 alleles with an average of 9.755 alleles per locus were obtained of which 97.07% of the loci were observed to be polymorphic. Nei's genetic diversity index (h) was 0.654 and the Shannon diversity index (I) was 0.647, indicating that the genetic diversity in barley genotypes studied was moderately high. At the population level, mean per cent of polymorphic loci (PPL) showed 98.37%, h = 0.388 and I = 0.568. Highest level of genetic diversity was observed in the Arsi population (with PPL = 100%, h = 0.439, I = 0.624); the lowest value observed was in population from Jimma (with PPL = 75.51%, h = 0.291, I = 0.430). Analysis of molecular variance (AMOVA) result showed significant genetic differentiation within and between populations (P<0.001), with 84.21% and 15.79% of the variation occurring within and among populations, respectively. Further, genetic variation analysis showed a coefficient of gene differentiation of 0.053 and a gene flow value of 4.467 among populations. The 384 barley genotypes were divided into seven genetic clusters according to STRUCTURE, neighbour-joining tree and principal coordinate analysis, correlating significantly with geographic distribution. These results signified presence of significant variations within and among populations (P<0.001), with the highest of the variation occurring within populations. The results will also assist with the design of conservation strategies, such as genetic protection via both in situ and ex situ conservation.

Genetic diversity of Ethiopian barley (Hordeum vulgare L.) genotypes based on multivariate statistical analysis for acid soil tolerance

Genetic diversity of Ethiopian barley (Hordeum vulgare L.) genotypes based on multivariate statistical analysis for acid soil tolerance

Impacts of Carbon Dioxide Enrichment on Landrace and Released Ethiopian Barley (Hordeum vulgare L.) Cultivars.

Barley (Hordeum vulgare L.) is an important food security crop due to its high-stress tolerance. This study explored the effects of CO2 enrichment (eCO2) on the growth, yield, and water-use efficiency of Ethiopian barley cultivars (15 landraces, 15 released). Cultivars were grown under two levels of CO2 concentration (400 and 550 ppm) in climate chambers, and each level was replicated three times. A significant positive effect of eCO2 enrichment was observed on plant height by 9.5 and 6.7%, vegetative biomass by 7.6 and 9.4%, and grain yield by 34.1 and 40.6% in landraces and released cultivars, respectively. The observed increment of grain yield mainly resulted from the significant positive effect of eCO2 on grain number per plant. The water-use efficiency of vegetative biomass and grain yield significantly increased by 7.9 and 33.3% in landraces, with 9.5 and 42.9% improvement in released cultivars, respectively. Pearson’s correlation analysis revealed positive relationships between grain yield and grain number (r = 0.95), harvest index (r = 0.86), and ear biomass (r = 0.85). The response of barley to eCO2 was cultivar dependent, i.e., the highest grain yield response to eCO2 was observed for Lan_15 (122.3%) and Rel_10 (140.2%). However, Lan_13, Land_14, and Rel_3 showed reduced grain yield by 16, 25, and 42%, respectively, in response to eCO2 enrichment. While the released cultivars benefited more from higher levels of CO2 in relative terms, some landraces displayed better actual values. Under future climate conditions, i.e., future CO2 concentrations, grain yield production could benefit from the promotion of landrace and released cultivars with higher grain numbers and higher levels of water-use efficiency of the grain. The superior cultivars that were identified in the present study represent valuable genetic resources for future barley breeding.

Spatial and temporal genetic variation in Ethiopian barley (Hordeum vulgare L.) landraces as revealed by simple sequence repeat (SSR) markers

BackgroundEthiopia is considered as center of diversity for barley (Hordeum vulgare L.) and it is grown across different agro-ecologies of the country. Unraveling population structure and gene flow status on temporal scales assists an evaluation of the consequences of physical, demographic and overall environmental changes on the stability and persistence of populations. This study was to examine spatial and temporal genetic variation within and among barley landrace samples collected over a period of four decades, using simple sequence repeat markers.ResultsResults from STRUCTURE, neighbor joining tree and discriminant analysis of principal component (DAPC) analysis revealed presence low-to-high genetic diversity among the landraces and grouped the landraces into three clusters. The cluster analysis revealed a close relationship between landraces along geographic proximity with genetic distance increases along with geographic distance. From analysis of molecular variance (AMOVA) in terms of collection year, it was observed that within-population genetic diversity much higher than between population and that the temporal differentiation is considerably smaller. The low-to-high genetic differentiation between landraces could be attributed to gene flow across the region as a consequence of seed exchange among farmers.ConclusionThe results demonstrate that this set of SSRs was highly informative and useful in generating a meaningful classification of barley germplasms. Furthermore, results obtained from this study also suggest that landraces are a source of valuable germplasm for sustainable agriculture in the context of future climate change and in situ conservation strategies following adaptation to local environments.

Agro-morphological traits-based genetic diversity assessment in Ethiopian barley (Hordeum vulgare L.) landrace collections from Bale highlands, Southeast Ethiopia

BackgroundCultivated barley (Hordeum vulgare L.) is one of the world’s important cereal crops. Ethiopia is claimed to be the centre of origin due to its high phenotypic diversity and flavonoid patterns. It is widely cultivated on subsistence bases and important in supporting the livelihood of local poor. However, the local landraces are currently under threat of severing genetic erosion. Hence, assessing the extents of its genetic diversity is timely in improvement and conservation.Methodology120 representative cultivated barley landraces have been collected from Bale highlands, Ethiopia, and tested at two locations using alpha lattice design. Data were collected on 21 agro-morphometric traits and analysed using MINITAB 19, SAS 9.4 and FigTree v1.4.3.ResultsMost morphotypes in each of the qualitative traits considered and mean performance values in most of the quantitative traits revealed wide range of variations suggesting existence of phenotypic diversity among the landraces. Analysis of variance also showed significant variations among the landraces. All the traits, except days to maturity and plant height showed a significant variation for location and treatment-location interactions revealing the high impact of environmental conditions on the variations. Estimates of the variance components also revealed a wider range of variations in most of the traits considered with eventual medium to low genotypic (GCV), phenotypic (PCV) and genotype–environment coefficients of variation (GECV). Estimates of heritability in broad sense (H2) is low (< 40%) in all the traits except in days to maturity. Grouping of the landraces showed poor geographic areas of collection-based pattern suggesting extensive gene flow among the areas.ConclusionThe landraces evaluated in the present study showed high morphological diversity. However, the effect of environment factor is pronounced and thus, multiple locations and years with large number of samples must be considered to exploit the available genetic-based variations for breeding and conservation of the crop.

Development of NIRS re-calibration model for ethiopian barley (Hordeum vulgare) lines traits to determine their brewing potential

Barley is one of the top five grain crops in Ethiopia, covering approximately 1 million hectares, and is grown for food, animal's feed and industrial purposes. Ethiopian Agricultural Research Institute (EIAR) is also conducting a barley research and breeding program with the aim of improving grain yield and resilience through screening lines. Sample materials used for the experiment were taken from 2018, 2019 and 2020 seasons to capture the variation in the growing year. As a result, the spectral data of the samples and the wet chemical data were generated using official international methods. Subsequently, a recalibration based on 280 samples of breeding lines of different genotypes, growing years and locations was developed in order to predict the protein, extract and friability content characteristics of important barley malt parameters. Wet chemical data were collected from processed/malted barley grains. A calibration model was created on the basis of the calibration software OPUS LAB 7.5 from Bruker Optics GmbH. The protein calibration (R 2 c = 0.90; RPD = 3.8) can be viewed as broadly applicable; the extract content (R 2 c = 0.88 and RPD = 2.8) and friability (R 2 c = 0.85 and RPD = 2.7) could be useful as well as a good predictive model for line screening. The calibration model was missing to predict long-range sample sources before the model range was expanded by recalibration process including different sample sources. Therefore, these NIRS models enable the selection of suitable food and malt barley genotypes at wide range. Since NIRS is fast and inexpensive, the barley improvement program can increase selection intensity, especially in the early testing phase. So the best precision of the NIRS recalibration discovered in this study enables to identify top candidate lines with a minimum of errors. • The aim was predicting grain barley quality trait using near infrared spectroscopy. • The 2018, 2019 and 2020 seasons of 280 barley genotypes were used for the study. • Models developed for protein, extract & friability from reference ^ spectral data. • Protein, extract & friability model predictive result is 3.8, 2.8 and 2.7 respectively. • A predictive model (>2.5) & (2–2.5) are excellent and good respectively.

Study on variability in resistance to barley yellow dwarf virus (BYDV-PAV) among Ethiopian barley (Hordeum vulgare L.) landraces

Ethiopian barley landraces are recognized as an important genetic resource with which a search for tolerance to biotic stresses is of worth. In present study, 585 barley (Hordeum vulgare L.) landraces collected from 13 barley producing zones of Ethiopia were evaluated along with 10 improved checks for resistance to BYDV serotype PAV under field conditions at Sinana and Goba during 2018 and 2019 cropping seasons. The trial was laid out in an augmented design consisting of six blocks. Data on disease incidence, severity and some agronomic traits were recorded. The result of analysis showed highly significant variations among landraces for disease incidence, severity and agronomic traits. The BYDV incidence and severity varied from 0.90 to 45.3% and 12.0 to 58.0%, respectively. Similarly, significant variations in terms of regions of origin, altitude classes and kernel row number were observed among landraces. Landraces originated from Arsi, Gojam, Bale and Gonder had significantly lower disease incidence and severity levels than others. Furthermore, landraces collected from altitude class IV (above 2500 m) and those with 6-row and irregular kernel type had lower disease severity. Segregation in infection was observed in some landraces due to a reduction of disease severity and 68 landraces showing lowest disease severity were selected. The resistant landraces identified in the present investigation can be utilized as good resource for barley improvement program targeting BYDV, which subsequently will help to incorporate the resistant genes into several elite backgrounds of barley.

Phenotypic diversity and population structure of Ethiopian barley (Hordeum vulgare L.) landrace collections

Landraces play a key role in crop breeding by providing beneficial trait for improvement of related crops and their genetic diversity studies are very important for breeding program and identification of parental lines. In this study, 585 barley (Hordeum vulgare L.) landraces collected from 13 agro-ecological zones of Ethiopia were evaluated along with 10 cultivars for their phenotypic diversity and population structure in relation to agronomic traits, resistance to major diseases and barley shoot fly. Data on 22 agronomic traits, three major diseases and barley shoot fly resistance-related traits were recorded. Univariate and multivariate approaches such as principal component and cluster analyses were applied to assess the genetic diversity and population structure. The analysis of variance indicated significant genotypic main, accessions x year and accession x environment interaction effects for almost all the traits evaluated. However, the accessions x environment interactions were mainly due to changes in magnitude rather than crossover types of interactions. The diversity analysis indicated that the population was highly structured according to kernel row-type, region (geographic) origin and altitude classes. Since the population is highly structured, appropriate statistical models will be needed when this population is used for association mapping studies. Eight principal components (PCs) in principal component analysis (PCA) accounted for the variation of 83.01%. The most related traits were included in the same PC, implying that results from PCA could give clues as to the relationship among traits. Though variability existed within and among clusters, useful germplasm clustered together. These materials are important sources of germplasm for the improvement of agronomic, disease and insect pest resistance traits. Keywords: Barley, diseases, genetic diversity, landraces, multivariate, shoot fly

Leaf rust resistance in barley accessions from Ethiopia

Currently, the problem of broadening the diversity of cultivated barley varieties based on the effective genes for resistance to the leaf rust causal agent Puccinia hordei has become relevant. In 2018–2019 the resistance of 925 barley accessions from Ethiopia to the northwestern (St. Petersburg, Pushkin) pathogen population was evaluated. The accessions were sown at a later date, favoring to severe plant damage. The resistance was assessed during the heading period and over the milk ripening stage using a point scale. The results of the experiments have indicated a low diversity of Ethiopian barley according to the studied trait. Only 4 accessions have been resistant to P. hordei, and 3 breeding lines (k-30810, k-30811 and k-30812) have been protected by the previously identified Rph7 gene, which efficiency has been decreasing&#x0D; in recent years. The accession k-21919 has possessed a high level of resistance to the pathogen (i.e. lack of damage symptoms) and therefore it can be recommended for utilization in barley breeding.

A Study on Variability in Resistance to Barley Yellow Dwarf Virus (BYDVPAV) among Ethiopian Barley (Hordeum vulgare L.) Landraces

Ethiopian barley landraces are recognized as an important genetic resource with which to search for tolerance to biotic stresses. Five hundred eighty five barley (Hordeum vulgare L.) landraces collected from 13 barley producing zones of Ethiopia were evaluated for resistance to BYDV serotype PAV under field conditions at Sinana and Goba during 2018 and 2019 cropping seasons. The trial was laid out in an augmented design consisting of six blocks. Data on disease incidence, severity and some agronomic traits were recorded. The result of analysis showed highly significant variations among landraces for disease incidence, severity and agronomic traits. The BYDV incidence and severity varied from 0.0 to 45.3% and 12.0 to 58.0%, respectively. Similarly, the variations among landraces in terms of regions of origin, altitude classes and kernel row number were significant. Landraces originated from Arsi, Gojam, Bale and Gonder had significantly lower disease incidence and severity levels than others. Furthermore, landraces collected from altitude class IV (above 2500m) and those with 6-row and irregular kernel type had lower disease severity. Segregation in infection was observed in some landraces due to a reduction of disease severity and 68 landraces showing lowest disease severity were selected. The resistant landraces identified in the present investigation can be utilized as good resource for barley improvement program targeting BYDV, which subsequently will help to incorporate the resistant genes into several elite backgrounds of barley.