Genetic diversity of Hordeum bulbosum L. accessions from Iran using simple sequence repeat markers

Bulbous barley grass, Hordeum bulbosum L., comprises the secondary genepool of cultivated barely, H. vulgare L.. The objective of this study was to evaluate the genetic diversity and structure of H. bulbosum using microsatellite markers originally developed in cultivated barley. We analyzed genetic variation at 15 microsatellite loci in 160 individuals of bulbous barley collected from 27 localities in Iran. A total of 97 alleles from 15 microsatellite loci were detected in all accessions. The number of alleles per locus ranged from 3 to 13, with an average of 6.53 alleles per locus. Analysis of molecular variance (AMOVA) attributed 82.25% of total diversity to the within populations genetic diversity, 12.78% to the between populations within regions and 4.96% to the variation between geographic regions. The genetic diversity decreases from the west toward the east of country. No clear correlation between genetic distances and geographical distances between populations of H. bulbosum was observed. It can be concluded that the genetic diversity is higher in more variable environments such as slopes of Zagros Mountains and lower in areas with more uniform conditions. Barley microsatellite markers found to be efficient and valuable molecular tools for analysis of genetic diversity of autotetraploid H. bulbosum populations. The genetic diversity is higher in more stressful environments such as slopes of Zagros Mountains in the west of Iran and lower in areas with optimal conditions like north of the country and areas near to Caspian Sea coasts. Also, we conclude that gene flow among natural populations is relatively high and that genetic drift has influence genetic variability of bulbous barley populations in Iran. According to the IUCN categories and criteria, this species are not assessed as treated or endangered in Iran, but the populations are highly endangered by successive drought and intensive grazing which result in losing genetic resources.

کلیدواژه ها:

bulbous barley ، genetic diversity ، gene flow ، Iran ، microsatellites