The genetic diversity of old and modern Siberian varieties of common spring wheat as determined by microsatellite markers

Abstract

The objective of this study was to assess genetic diversity within old and modern common spring wheat (Triticum aestivum L.) varieties cultivated in Siberia and to find out whether old Siberian varieties could be a potential source for genetic diversity in modern wheat breeding in Siberia. A set of 54 varieties was analysed using 22 wheat microsatellite markers (WMS), determining 23 loci located on 19 different chromosomes. In total, 151 alleles were detected with an average of 6.6, ranging from three to 11 alleles per locus. The average genetic diversity value (polymorphic information content) was 0.70. WMS located in the B genome produced more alleles per locus (7.6) compared with WMS located in the A (6.0) and D (6.0) genomes. Genetic similarity values between varieties ranged from 0.19 to 0.96 and were used to produce a dendrogram. With a few exceptions the varieties studied were clustered in two nearly equal groups consisting of predominantly old (released before 1960) and modern (released in 1960-90s) varieties, respectively. Genetic diversity values within these two groups were similar with 0.60 and 0.58, respectively. The numbers of group-specific alleles were 34 and 29, respectively. A significant variation in frequencies of 79 shared alleles was observed. The results obtained by using genomic microsatellite sequences demonstrated that breeding has not resulted in a decrease in the genetic diversity in Siberian spring wheat. However, significant quantitative and qualitative changes in allelic frequencies of different loci were detected. It may be suggested, that old Siberian common spring wheat varieties are a potential basis for genetic diversity in modern wheat breeding in Siberia.