Genetic diversity of Shaanxi soybean landraces based on agronomic traits and SSR markers
Genetic diversity of a primary core collection of 91 soybean landraces from Shaanxi Province, China, was analyzed using simple sequence repeat (SSR) markers and agronomic traits. A total of 250 alleles were detected in the 91 soybean accessions, with a mean of 7.14 alleles per locus. The mean of polymorphism information content (PIC) was 0.26, ranged from 0.11 for Satt184 to 0.60 for Satt242. UPGMA cluster analysis and PCA analysis clearly showed that, 91 accessions formed two major clusters which generally correspond to geographic origin. Cluster I contained 76 soybean landraces and it was further separated into five subgroups (I-1 to I-5). Cluster II (northern group) included 15 accessions from northern Shaanxi. Group I-1 (Guanzhong group) contained 19 landraces, with 16 from Guanzhong, 3 from northern Shaanxi. Group I-2 (southern group I) composed of 13 accessions from southern Shaanxi and 2 from Guanzhong. Group I-3 (mixture group) contained 18 landraces, with 10 landraces from Guanzhong and 8 from southern Shaanxi. Group I-4 (southern group II) contained 21 accessions, of which 20 from southern Shaanxi and 1 from northern Shaanxi. Group I-5 (southern group III) included only 2 southern Shaanxi landraces. AMOVA analysis showed that, a significant proportion of variance (94.28%) was due to variation within populations.
Key words: Soybean (Glycine max(L.) Merr), landraces, genetic diversity, simple sequences repeat (SSR).