Genetic diversity between ex situ and in situ samples of Agropyron cristatum (L.) Gaertn. based on simple sequence repeat molecular markers

摘要

Fifty-five populations of Agropyron cristatum (L.) Gaertn., both ex situ conserved and in situ collected and originating from northern China, were analysed using 29 polymorphic simple sequence repeat (SSR) primers mapped on the wheat genome. The study showed ex situ and in situ populations had different numbers of alleles and allelic frequencies in 17 of the 29 primer pairs. The SSR markers revealed significant genetic differences between gene bank-conserved and in situ recollected populations from similar ecogeographical regions. AMOVA analysis indicated 15% of the total variation resided between groups, and 85% resided within groups. According to a dendrogram generated by unweighted pair group method with arithmetic average cluster analysis based on Nei's genetic distance matrix and principal coordinate analysis, recollected and gene bank-conserved populations from the same regions were distinguished. The results indicate that both in situ and ex situ conservation play complementary roles in the conservation of A. cristatum.