Mapping Quantitative Trait Loci for Soybean Quality Traits from Two Different Sources

Abstract

Soybeans are economically and agriculturally the most important legume in the world, providing protein and oil to the food and animal feed industries and base ingredients for hundreds of chemical products. Their value could be enhanced, however, if the oil and protein content remained high and the oligosaccharide and phytate contents were lowered to make soybeans more acceptable for human and animal consumption. A soybean population of 55 families segregating for genes controlling quality traits was chosen for this study. Both parental lines have high sucrose and low stachyose. The former contains a high level of phytate while the latter is low phytate. The objective of this experiment was to determine whether or not both parents had the same gene(s) for low stachyose. An additional objective was to determine quantitative trait loci (QTL) controlling quality traits: sucrose, stachyose and phytate. An acetonitrile precipitation method and a modified colorimetric method were used to determine amounts of sugars and phytate, respectively. The phenotypic data for stachyose was analyzed and it was determined that two recessive genes control low stachyose content in this population. A map was constructed using 141 SSR markers and 15 molecular linkage groups (MLGs) were identified. After analyzing trait and marker data in QTL Cartographer, potential QTL were found on MLGs: B1, C2, D1b, F, M and N. Sucrose and stachyose QTL were identified on B1, C2, M and N. Phytate QTL were observed on B1, D1b, F and N. The markers identified for quality traits in this population may be useful in marker-assisted selection and the germplasm should be useful for the development of a cultivar.