Molecular markers associated with β-conglycinin deficiency in soybean

Abstract

Seed storage protein β-conglycinin of soybean contains major allergens in its subunits, and displays a lower amino acid score and lower functional gelling properties than glycinin. Therefore, decrease in the content of β-conglycinin is one of the objectives of soybean breeding programs. A β-conglycinin-deficient mutant QT2 was identified from a wild soybean in Kumamoto prefecture, and the phenotype was found to be controlled by a single dominant gene Scg-1 (Suppressor of β-conglycinin). Fukuyutaka and a near-isogenic line of Fukuyutaka, QY7-25 harboring the Scg-1 gene were used for development of DNA markers associated with β-conglycinin deficiency. Ten single nucleotide polymorphisms (SNPs) in the β subunit genes were detected between Fukuyutaka and QY7-25. Two β subunit gene loci were found to cosegregate with β-conglycinin deficiency with the DNA marker based on SNPs in a F2 population derived from a cross between Fukuyutaka and QY7-25. The DNA marker also enabled to detect polymorphisms between QY7-25 and major soybean cultivars and could be used as a practical tool for the introduction of Scg-1 gene into soybean. The chromosome region associated with β-conglycinin deficiency was located on linkage group I of a soybean genetic linkage map with the developed marker using a F2 population from the parents, Misuzudaizu and Moshidou Gong 503.