Genetic Diversity Of Characters Of β-conglycinin In Seeds Of Soybean Germplasm Resources

Soybean seeds are one of important proteinaceous-resources for mankind. Soybean seed proteins have higher content, better balance of amino acids and more excellent physicochemical-properties such as oil-absorbability and emulsification than cereal proteins, and thus are widely utilized in the various fields including food, medicine, chemical industry and so on.β-conglycinin(7S) and glycinin(11S) are the major proteins in soybean seed. Of them,β-conglycinin, which is composed of 76kDaα', 72kDaαand 52-54kDaβsubunits and approximately account for 30% of the total seed proteins, is greatly responsible for the quality of soybean proteins.In this study, the purity ofβ-conglycinin was obviously increased to 98% by performing conditions optimization of the key links in the process of extraction and isolation of the protein; the genetic resources having five phenotypes ofβ-conglycinin were sought by screening 289 soybean germplasms using the SDS-PAGE technique and gel imaging system. These phenotypes are the control type ofβ-conglycinin, higher MW type ofα' subunit, polymorphic type ofα' composition, lacked type ofβsubunit and top-lacked type ofβsubunit band, respectively. These results indicate the genetic diversity of biochemical characters ofβ-conglycinin in soybean germplasms, reveal the complexity of molecular composition and genetic mechanism ofβ-conglycinin in soybean seed. The genetic resources considered to be useful materials for the overall understanding of genetic mechanism regulating synthesis and deposition ofβ-conglycinin and the breeding for diversification of quality of soybean proteins.