Soybean Research

Molecular mapping and characterization of genes underlying low cadmium uptake and protein composition
Dr. Kangfu Yu, Agriculture and Agri-Food Canada

Development of low cadmium accumulating soybean varieties is of fundamental importance to the competitiveness of the Ontario soybean industry for Asian markets. Incorporation of a low cadmium-accumulating trait into adapted variety through conventional breeding is very difficult because there is no easy, economic and efficient method available to measure cadmium content in soybean seeds.

This problem would be easily solved if molecular markers linked to genes controlling low cadmium content were developed. Molecular markers for low cadmium accumulation will facilitate the development of low cadmium accumulating soybean cultivars for Ontario soybean growers. Soy food quality is largely determined by soy seed protein composition. Glycinin (11S) alone accounts for approximately 50 percent of the total seed storage proteins. As a consequence glycinin plays an important role in the properties of food made from soybeans.

Functional properties of soy proteins for food, such as gelation and emulsification and thermal stability, are closely related to the composition of their storage protein subunits. Understanding the genetic control of the protein subunits will help us to manipulate their combination for developing superior soybean cultivars for soy food production.

In this project molecular markers were developed and/or used to assist selection of soybean plants for resistance to pests including Soybean Aphid (SBA), Soybean Mosaic Virus (SMV), Soybean Cyst Nematode (SCN) and Phytophthora Root Rot (PRR). The utilization of marker-assisted selection (MAS) helps breeders speed up the development of soybean cultivars possessing single and/or multiple pest and disease resistance for Ontario soybean growers. The MAS technology is fast, accurate and efficient as it does not need artificial inoculation with the pathogens. The cultivation of cultivars with natural resistance is the most effective and environmentally sound approach to reduce crop losses caused by SCN, SBA, SMV and PPR.

Ultimately, this project aims to map genes underlying low cadmium uptake and develop molecular markers tightly linked to the genes for use in marker-assisted selection of food type soybean. We are also looking to characterize genes that determine the presence or absence of specific soybean storage protein subunits for better use in soy food production.