Physiological and Molecular Analysis of Soybean Seed Longevity and Validation of Candidate Markers

Background: Seed longevity is a major constraint in soybean seed production. The major focus of this study is to analyze the physiological and molecular changes associated with seed longevity and identify promising germplasm which are good storers for soybean breeding program. Methods: Nineteen genotypes were studied for seed longevity using accelerated ageing test and genetic integrity based on SSR marker data. Genotypes were clustered into distinct groups based on seed morphological and physiological parameters (Mahalanobis D2 analysis). SSR markers for seed longevity were validated in the germplasm. Result: Per cent reduction in germination after accelerated ageing was significantly and positively correlated with traits associated with seed storability such as seed length, seed width, seed thickness and 100 seed weight and negatively correlated with seedling vigour indices. Hence, it would be worthwhile to rely upon these parameters for enhancing the seed storability in soybean. Genetic integrity of the germplasm was evaluated based on SSR markers in accelerated ageing seeds. SSR markers (Satt 285, Satt 534, Satt 538, Satt 281, Satt 162, Satt 631 and Satt 371) revealed significant association for the seed longevity characters such as seed length, seed width, seed thickness and seed weight. Candidate markers (Satt 371, Satt 281, Satt162, Satt 285, Satt 534) which can differentiate the soybean genotypes for storability have been identified in this study. The genotypes were grouped into seven clusters with monogenotypic cluster III (PSPB23) having minimum reduction in germination after accelerated ageing.