Genetic polymorphism and hybridity testing in elite soybean parental combinations

Abstract:

The present study evaluated parental polymorphism and confirmed hybridity among four soybean cross combinations using simple sequence repeat (SSR) markers. Four elite soybean genotypes, namely AMS MB 5-18, AMS 100-39, NRC-150, and Swarna Vasundhara, were used as parental lines for the development of F₁ populations. A total of 220 SSR markers distributed across 20 linkage groups were screened, of which 145 produced clear amplification and 100 exhibited polymorphisms among the parental genotypes. The identified polymorphic markers showed variation in polymorphism and Polymorphism Information Content (PIC) across the four parental combinations. Two SSR markers, Satt640 and Sat_119, were polymorphic across all four parental combinations and exhibited high PIC values (> 0.85), indicating their potential utility for parental discrimination and background selection. In addition, a null Kunitz trypsin inhibitor (KTI)-specific marker was used to identify F₁ plants carrying the null kti allele derived from NRC-150. Among 36 progenies evaluated from the NRC-150 cross combinations, five plants produced the expected 420 bp amplicon and were identified as putative F₁ hybrids carrying the null KTI allele. The polymorphic SSR markers and KTI-specific marker identified in the present study provide useful molecular resources for parental selection, hybridity confirmation, and marker-assisted breeding aimed at developing food-grade soybean with reduced anti-nutritional factors.