Wheat microsatellite diversity of a genebank collection in comparison to registered varieties.

摘要

The potential of a germplasm collection for improving cultivars depends on the presence of novel genes or alleles that are not found in the existing cultivars. We compared the diversity of 19 microsatellite markers in 994 v^heat accessions of the Genebank Gaterslehen with the diversity found in 502 modern European varieties (VE). The chosen genebank accessions are a geographical representation of approximately 10% of all Triticum aestimm accessions maintained at Gaterslehen and are subdivided into 450 accessions of European origin (GE) and 544 accessions collected outside of Europe (GW). A total of 198 alleles was found in the varieties versus 280 alleles in the European genebank accessions and 323 alleles in the non-European accessions. In total the 994 genebank accessions contained 339 alleles of which 147 alleles were unique to the genebank accessions and not found in the varieties. The highest incidence of genebank unique alleles was observed in accessions originating from North Africa and theMiddle and Near East of Asia. Deviating frequencies of specific microsatellite alleles occurred in 26, 24 and 28 cases (P<0.000001) for VE, GE and GW, respectively, and may be caused by selection processes during the development of commercial varieties.These results confirm the assumption, that genebank collections harbour ample genetic diversity that is not found in existing varieties and that provides a potential source of novel alleles for future breeding.