Seed longevity studies in wild type, cultivated and inter-specific recombinant inbred lines (RILs) of soybean [Glycine max (L.) Merr.]

Loss of seed viability is a serious hurdle in production and ambient seed storage of soybean. Understanding the factors affecting seed viability, and identification of soybean genotype(s) with higher viability is critical for higher soybean production. In this study, seeds of 125 soybean genotypes of three different species [Glycine tomentella Hayata, Glycine max subsp. soja (Siebold & Zucc.) H. Ohashi, and Glycine max(L.) Merr.] and 25 RILs (Glycine soja x Glycine max) were tested for germination immediately after harvest followed by 1, 2 and 3 years of ambient storage. Fresh seeds of all the genotypes recorded 78-99% germination with a mean of 94.02%. However, the mean value of per cent germination of all the genotypes after 1, 2 and 3 years of ambient storage decreased and found to stand at 79.51%, 52.24% and 29.18%, respectively. Among the genotypes tested, G. tomentella accession registered highest seed storability followed by G. soja, RILs and G. max. After 3 years of storage, 14 wild type genotypes and 3 RILs found to maintain > 70% germination and, were identified as 'good storers'. Genetic divergence studies via k-mean clustering and principal component analysis grouped all genotypes in three clusters. Seed viability was significantly and negatively correlated with electrical conductivity. Good storers found to be having slow imbibition rate than poor storers in initial hours of imbibition. The good storing genotypes identified in this study will serve as an elite soybean genetic resource in developing the soybean cultivars with better seed longevity.