Inheritance of Cgy1 gene and Ti gene in Mature Soybean Seed

Abstract

Soybean proteins are widely used for human and animal feed in the world. β-conglycinin protein exhibits poor nutritional and food processing properties and Kunitz trypsin inhibitor (KTI) protein is a main anti-nutritional factor in soybean seed. The objective of this research was to identify the inheritance of cgy1 gene and ti gene for the improvement of soybean cultivar with no KTI proteins and low amount of β-conglycinin. F2 population was made by crossing between “Gaechuck2ho”(α′-subunit present Cgy1Cgy1, KTI protein absent titi) and PI506876 (α′-subunit absent cgy1cgy1, KTI protein present TiTi) parent. A total of 434 F2 seeds were obtained and analyzed for the segregation of α′-subunit protein and KTI protein using SDS-PAGE. The segregation ratio of 3 : 1 for Cgy1 locus (310 Cgy1_ : 124 cgy1cgy1) and Ti locus (339 Ti_ : 95 titi) were observed. Segregation ratios of 9 : 3 : 3 : 1 (241 Cgy1_Ti_: 69 Cgy1_titi: 98 cgy1cgy1Ti_: 26 cgy1cgy1titi) between Cgy1 gene and Ti gene in F2 seeds were also observed (χ2= 5.367, P = 0.10 - 0.20). This data showed that Cgy1 gene was inherited independently with the Ti gene in soybean. These results will be useful in breeding program for selecting the line that does not exhibit or lacks both α′-subunit protein and KTI protein in soybean.