Assessing Genetic Diversity of Chinese Cultivated Barley by STS Markers

To assess the genetic diversity among China’s cultivated barley, sequence tagged site (STS) marker analysis was carried out to characterize 109 morphologically distinctive accessions originating from five Chinese eco-geographical zones. Fourteen polymorphic STS markers representing at least one in each chromosome were chosen for the analysis. The 14 STS markers revealed a total of 47 alleles, with an average of 3.36 alleles per locus (range 2–8). The proportion of polymorphic loci per population averaged 0.84 (range 0.71–1.00); the mean gene diversity averaged 0.39 (range 0.28–0.49). The means of P and H_e were highest in the Yangtze reaches and Southern zone (P = 1.00; H_e = 0.46) and lowest (P = 0.71 He = 0.28) in the Yellow river reaches zone. The STS diversity in different zones is quite different from the morphology diversity. The STS variation was partitioned into 17% among the zone and 83% within the zone. Both cluster and principal coordinate analyses clearly separated the accessions into a dispersed group (mostly two-rowed barley with a lower mean GS value) and a concentrated group (mostly six-rowed barley with a higher mean GS value) according to the spike characteristic with only a few exceptions. The accessions from the Qinghai-Tibet plateau formed a distinctive subgroup and can be distinguished from the concentrated group. The role of Tibet in the origin and evolution of cultivated barley has been discussed.