Development of Soybean EST-SSR Markers and Their Use to Assess Genetic Diversity in the Subgenus Soja

Developing expressed sequence tag-derived SSR (EST-SSR) markers is imperative in genetic research. In this paper, we reported 37 EST-SSR markers which were developed from 286 unigenes obtained from soybean eDNA library. Among the 286 markers designed for the 4 accessions of Glycine max and 6 of its wild progenitor (G. soja) within the subgenus Soja,209 markers amplified DNA fragments, taking 73.1% and 37 markers appeared to be polymorphic, which was 12.9% of the total. The 37 loci detected a total of 142 alleles, while the PIC values varied from 0.194 to 0.794. Both the number of alleles per locus and PIC value were significantly related to the SSR motif. Six EST-SSR loci may be fixed for different alleles between G. max and G. soja since they were particularly polymorphic among the 6 G. soja accessions. A neighbor-joining tree placed the G. max accessions together as a group within the G. soja, though the average genetic distance among G. soja accessions was much higher. These new EST-SSRs markers will be useful for genetic diversity analysis, genetic mapping construction and gene discovery in Soja subgenus.