Genetic studies on seed coat permeability and viability in RILs derived from an inter-specific cross of soybean [Glycine max (L.) Merrill]

Soybean seeds loss viability very rapidly during ambient storage in the tropical and sub-tropical environments. In this study, interrelationship between seed coat permeability and viability over periods of ambient storage was assessed using a set of 217 recombinant inbred lines (RIL) developed from an inter-specific cross between wild type (Glycine sofa) accession DC2008-1 and cultivated (G. max) variety DS9712. G. sofa seeds were tiny, black, impermeable and highly viable while G. max seeds were large, yellow, permeable and poorly viable during ambient storage. Seed coat permeability and viability of the fresh, one-year and two-year-stored seeds (stored in room temperature, ay. 25 +/- 2 degrees C and 65 +/- 5% RH) were tested as per standard protocols in completely randomized design with two replications. Significant variation was found among genotypes for the seed viability, permeability, periods of storage and their interactions. Permeability of the seed coat increased with the period of storage. In the fresh, one-year and two-year stored seeds, the seed coat permeability was 62.87, 75.17 and 90.52%, respectively. Viability of the seeds was negatively correlated with period of storage and seed size. In the fresh, one-year and two-year-stored seeds, average viability was 90.7, 75.6 and 54.1%, respectively. Scanning electron microscopy (SEM) indicated presence of intact hilum, strong hourglass cells and non-cracked seed coat in the highly viable seeds. A set of 24 RILs were found that maintained higher viability (>= 80%) with varying degree of permeability after two years of storage. Among the highly viable RILs, more were black seeded. RIL Nos. 7-12-3, 7-24-1, 13-2-2, 13-31-4 found to maintain both viability and permeability in higher order during storage and would pave the way for development of soybean genotypes with high viability and permeability.