Novel set of groundnut SSR markers for germplasm analysis and interspecific transferability

Cultivated groundnut (Arachis hypogaea L.), is an important oil seed crop grown mostly in tropical and subtropical regions of the world. However, it suffers with narrow genetic diversity due to genetic bottlenecks such as the recent polyploidization and self pollinating nature of the crop. In such crop species, simple sequence repeats (SSRs), as compared to other marker systems such as restriction fragment length polymorphisms (RFLPs), randomly amplified polymorphic DNAs (RAPDs) and amplified fragment length polymorphisms (AFLPs) have been found more informative for genetic studies and breeding applications. Therefore, with an aim to develop new SSR markers in groundnut, a SSR-enriched library was constructed from the genotype ICGV 86031. Out of 29 SSRs isolated, primer pairs were designed for 23 SSR loci, of which 14 (61%) primer pairs yielded scorable amplicons. Eight (57%) primer pairs showed polymorphism among 23 groundnut genotypes that are parents of different groundnut mapping populations at ICRISAT, India and EMBRAPA, Brazil. The polymorphism information content (PIC) for polymorphic SSR markers ranged from 0.13 to 0.36, with an average of 0.25. Newly isolated SSR loci showed good interspecific transferability rates ranging from 13% to 100% across seven legumes and 43% to 100% within the seven legumes. The present set of newly developed SSR markers enriches the existing groundnut SSR repertoire and the transferable SSR markers will be useful for comparative genome analysis in related legumes.