Allele Diversity of Hordein-Coding Loci Hrd A and Hrd B in Cultivated (Hordeum vulgare L.) and Wild (Hordeum spontaneum C. Koch) Barley from Syria (as a Part of the Fertile Crescent)

Аннотация

Starch gel electrophoresis was performed to study polymorphism of hordeins encoded by the Hrd A and Hrd B loci in 60 local accessions of cultivated barley and 23 accessions of wild barley from Syria. In H. vulgare and H. spontaneum, 37 and 28 alleles, respectively, for the Hrd A locus were identified, and 54 and 38 alleles, respectively, for the Hrd B locus were identified. For H. vulgare, the allelic frequencies ranged from 0.0017 to 0.2250 and from 0.0017 to 0.2182 for the Hrd A and Hrd B loci, respectively. For H. spontaneum, the allelic frequencies for these loci varied from 0.0087 to 0.1391 and from 0.0087 to 0.0696. Only three out of 62 alleles of Hrd A were common between Syrian accessions of H. spontaneum and H. vulgare, while no common alleles were found among 92 alleles of Hrd В. We noted that the hypothesis of barley domestication in Southeastern Turkey/Northern Syria in approximately 9000–8000 BC is based on archaeological findings. However, the earliest records of utilization of barley grains in the Middle East were found in the site Ohalo II near the Sea of Galilee, which was dated back to 17000 BC. The age of wild and cultivated barley grains detected in archaeological findings in Egypt was dated back to 18000 BC. We concluded that Syria cannot be considered as barley domestication center. At the same time, Syrian H. spontaneum could have contributed some alleles of hordein-coding loci to the gene pool of H. vulgare owing to introgression resulting from spontaneous hybridization over the course of crop diffusion from the domestication center outward.