Abstract:

Thirteen reproducible and informative SSR primer pairs were selected from the 46 candidates. A representative set of 316 cowpea genetic resources from China, Africa and other countries of Asia, were analyzed by SSR methodology using these informative primer pairs. A total of 47 alleles were detected with an average of 3.692 alleles per SSR primer pair, and on an average 2.003 alleles from each SSR primer pair were effective. According to integrated evaluation, five SSR primer pairs, VM16, VM26, VM20, VM25, and VM23, were most effective for genetic diversity studies of cowpea. The dendrogram by UPGMA cluster analysis showed that 260 accessions of the 316 were distinct and revealed enough genetic diversity for identification and classification of accessions within Vigna unguiculata. There was a clear difference between foreign and Chinese genetic resources. Within Chinese accessions, 8 distinct groups including two northern groups, four southern groups and two complex groups, were detected, indicationg that the Chinese breeding lines have a narrow genetic background.

Key words: Pigeonpea, SSR, Cluster analysis, Genetic diversity