Heritability and correlations among food-grade traits in soybean

Societal changes towards healthier food have helped uncover the nutritional value and health benefits of soybeans. Hence, the development of food-grade specialty cultivars has become a niche market for soybean breeders and producers. The objectives of this study were to estimate the heritability and correlations among five food-grade traits: seed size, protein, sucrose, raffinose, and stachyose concentration. We evaluated 98 recombinant inbred lines derived from a cross between a high protein line and a large-seeded cultivar with moderate sucrose concentration at two locations in Arkansas for 2 years. Although food-grade traits were significantly affected by year and location interactions, larger variability was attributed to differences among lines than to the line by location interaction for seed size, protein, sucrose and stachyose. Heritability estimates ranged from 0.46 to 0.86, so selection for genotypes with specific combination of these traits should be reliable. Because of a negative correlation (-0.68), selection for high sucrose will likely be accompanied by a reduction in protein. Our findings will help breeders develop efficient strategies for breeding food-grade soybean cultivars.