Genetic structure and geographical differentiation in barley landraces based on storage proteins

ABSTRACT: Although, It is now generally accepted that domestication of barley is assumed to have taken place from Hordeum vulgare L. subsp. spontaneum, however, it is not clear whether cultivated barley is of monophyletic origin or the domestication events happened in other parts of the world besides the Fertile Crescent. In this study polymorphism of storage proteins were used to investigate the genetic diversity and geographical differentiation of 116 barley landraces from various regions in the Fertile Crescent (Syria, Turkey and Iran) and outside of it (Tajikistan, Kyrgyzstan and Kazakhstan). Eighty-seven different monomeric prolamins patterns were identified, of which 32 different patterns were in the region of ?, 30 in the B, and 27 in the region of ? prolamins. The D, C and B hordein zones were identified by 5, 14 and 12 bands. In this analysis, 5, 23 and 30 patterns were observed for the D, C and B areas, respectively. In analysis of monomeric prolamins such as hordeins, there were many patterns specific to each zone. These patterns were present predominantly in specific zones showing some advantage over other storage protein patterns in adaptation to the conditions prevailing in these zones or these are closely linked with genes having adaptive value to the specific environment. The number of patterns and genetic diversity index based on storage proteins (both hordeins and monomer prolamins) was higher for Syria, Iran and Turkey accessions than for other countries. The high level of polymorphism in this collections barley would agree with the suggestion that Fertile Crescent is a first possible domestication center of this crop.