Food Grade Soybean Breeding, Current Status and Future Directions

Abstract

Soybeans possess average 20% oil and 40% protein content and are a major source of protein and fatty acids in human and animal nutrition. Soybean cultivars are classified as commodity type, which are used for edible or industrial oil and animal feed, and food-type, which are used for human consumption in fermented foods and non-fermented foods. Major breeding targets for food grade soybeans are high protein and sucrose content. Developing cultivars with desired seed size and appearance depends on the type of soyfood for which the soybeans are destined. Seed with high protein content (>45%), low oil content, high sucrose, and low oligosaccharide content are suitable for making soymilk and tofu. For soyfood such as natto, soybean seed with a high content of carbohydrates are preferred. Since, molecular markers linked to the target food traits have been developed, transfer of the food grade traits among soybean varieties is possible through marker-assisted selection (MAS) to track the target gene/QTLs. Introgression of wild soybean alleles through genomics assisted breeding (e.g., GWAS, haplotype blocks, NIL, etc.), high-throughput phenotyping, mutagenesis and genome engineering/editing would improve protein without yield drag, pleiotropic effects, and background/allelic effects in breeding food grade soybean.