A Stack of Recessive Alleles of Kunitz Trypsin Inhibitor, Lectin, and Stachyose in Soybean

Abstract

Soybean [Glycine max (L.) Merr.] is one of the major food sources of protein, oil, carbohydrates, isoflavones, and other nutrients for both humans and animals. However, soybean seeds contain antinutritional factors, such as lectin protein, Kunitz Trypsin Inhibitor (KTI) protein, and stachyose. The objective of this research was to stack recessive alleles for development a triple recessive genotype, titilelers2rs2, with low KTI protein, lectin protein, and stachyose contents. Three parents (Gaechuck#2, PI200508, and 14G20) were used to develop the breeding population. The presence or absence of the lectin and KTI proteins was detected by western blotting. The stachyose content in mature seeds was determined by HPLC. Agronomic traits, such as plant type, plant height, maturity date, lodging, seed quality, and 100-seed weight, were evaluated for the four F3 plant strains. One F4 plant strain with the desired agronomical traits was selected. One new strain with the triple recessive titilelers2rs2 genotype was developed. The plant height of the new strain was 51 cm and the 100-seed weight was 31.0 g. The new strain had a yellow seed coat and yellow hilum. The stachyose content of the new strain was 3.8 g/kg. One strain developed in this research will be used to produce improved yellow soybean cultivars that are free of lectin and KTI proteins and low in stachyose content.