MAPPING QTL FOR SEED PROTEIN AND OIL CONTENT IN 8 SOYBEAN POPULATIONS

Soybean [Glycine max (L.) Merr.] seeds contain high levels of protein and oil useful for human consumption. Increasing emphasis in breeding programs to produce soybeans with specific protein or oil content for specialty markets demands that more efficient manipulation of these tr aits be achieved. The objective of this study was to evaluate eight di fferent soybean populations from the midwestern USA for genetic marker s linked to seed protein and oil content. The populations were derived from the breeding programs at the Univ. of Minnesota, the Univ. of Ne braska, and Purdue Univ.-USDA-ARS. Each population consisted of betwee n 69 and 100 individuals and was mapped with 21 to 85 restriction frag ment length polymorphism markers. The F-2-derived populations were gro wn in field tests in 1992, 1993, and 1994 in the state in which they o riginated. Single factor analysis of variance was used to detect signi ficant associations between markers and traits. Environmentally stable and environmentally sensitive quantitative trait loci (QTL) were iden tified for both protein and oil contents in all eight populations. The identified QTL were sensitive to both environment and genetic backgro und although some common QTL were identified in multiple populations a cross several years. The results show that a number of QTL affect thes e traits and that markers could potentially be used in breeding progra ms designed to alter the seed protein and oil content.