Genetic diversity within landraces of barley (Hordeum vulgare L.) and its implications on germplasm collection and utilization

Knowing the extent of genetic variability among and within barley accessions provide bases of selection for breeders. However, given the heterogeneous nature of the germplasm, genetic information about barley landraces stored in gene bank of Ethiopia is not well archived. Therefore, genetic diversity study was conducted among and within 20 barley accessions represented by 194 barley plants. The accessions originate from 10 different geographic regions of Ethiopia covering a wide range of altitudes. The accessions were tested using 15 simple sequence repeat markers (SSRs). The SSR markers detected 57 alleles ranging from two (GBM1042) to seven (Bmac0040) alleles per marker indicating the genetic diversity in the barley plants. The allelic diversity across geographic regions and altitude reveals that barley accessions collected from mid and low altitudes of Ethiopia show high allelic diversity compared to accessions originating from high altitudes. Analysis of molecular variance results based on geographic regions (64.39%) and altitude classes (64.04%) also showed the highest variation within accessions compared to among accessions and groups. Both geographic regions and altitude-based genetic structure analysis detected two sub-populations. The individual assignment following the altitude of collection revealed the role of altitude in shaping the genetic diversity observed in barley populations. In general, the result of this study shows that each single barley line within the accessions should be considered as a potential source of genetic material and must be treated distinctly during germplasm collection and utilization.