Characterization, Identification And Genetic Analysis Of Mutant Characters For β-conglycinin In Soybean

Soybean seed protein is account for more than 40% of the seed, and it contains 8 essential amino acids which the mankind and animal body can’t synthesis, thus is important amino-acid source. The major storage proteins in soybean seed are glycinin and β-conglycinin. The β-conglycinin of them is mainly composed of 76 kDa α’,72 kDa a and 52-54 kDa β subunits. The proteins have stronger immunogenicity causing the allergic reaction in the mankind and animal body, and the property of lower sulfur-containing amino acid which limits absorption of other amino acids in soybean protein, thus are greatly responsible for quality of soybean proteins. In current research at home and abroad, mutants for β-conglycinin are mainly obtained by screening soybean germplasms or mutagenesis, and considered to be valuable materials for genetic study and breeding for quality of soybean proteins.The typical soybean germplasms with the various characters of β-conglycinin have been obtained in the previous study in this laboratory. In this study, analyses of hereditability and genetic behavious were performed using SDS-PAGE, crossing and self-crossing methods. Two typical soybean germplasms formerly known as zeibutou and huangdou were confirmed to have the inheritable mutant-characters namely β lack and higher molecular weight of α’, compared with the soybean germplasm (qiudadou 93025) with the wild character of P-conglycinin, and were named β-Lack and α’-HM as mutants, respectively; The alteration of β-Lack character were found to result from recessive mutation of a monogene, and the α’-HM character was found to be controlled by a dominant monogenic-mutation. The mutants are good genetic resources used for the overall understanding of genetic mechanism regulating synthesis and accumulation of β-conglycinin in soybean, and breeding for quality of soybean proteins.