Stacking of recessive alleles for antinutritional factos of P34, lectin, KTI and 7S α′ subunit proteins in soybean [Glycine max (L.) Merr.]

Soybean [Glycine max (L.) Merr.] is an excellent source of protein for humans, but several allergenic and antinutritional components such as P34, lectin, Kunitz Trypsin Inhibitor (KTI), and 7S α′ subunit proteins exist in the raw mature seed. Genetic elimination of these factors would be the appropriate method to improve soybean food quality. The objective of this research was to develop a new soybean line with a tetra null recessive genotype (titilelecgy1cgy1p34p34) based on Mendelian inheritance. Four germplasms were used to develop the tetra null strain. A total of 322 F2 seeds were obtained from the cross of parent 1 and parent 2. For four proteins of KTI, lectin, 7S α′ subunit and P34, and segregation ratio of 107:30:37:8:35:9:14:3:33:9:14:0:13:3:5:2 was observed (χ2 = 9.41, P = 0.9 ~ 0.5). Two F2 seeds possessing the tetra null genotype (cgy1cgy1titilelep34p34) were selected. Confirmation of the Tetra null genotype (titilelecgy1cgy1p34p34—absence of KTI, lectin, 7S α′ subunit and P34 proteins) was verified on the random F3 seeds of the two lines selected. The seed color for both selection lines was yellow and the hilum color was buff. The seed weights (g/100 seeds) for the two selected lines were 12.2 and 12.0 g. This paper is the first to investigate the genetic segregation ratio and selection of tetra null genotype for four proteins of P34, lectin, KTI and 7S α′ subunit proteins in soybean.