Putative Alleles for Increased Yield from Soybean Plant Introductions

Abstract

Improving seed yield of soybean [Glycine max (L.) Merr.] is an important breeding goal. The objective of this study was to evaluate two soybean PIs as sources of alleles for the enhancement of seed yield in North American cultivars. A population of 167 F5–derived lines was developed from a cross between ‘BSR 101’ and the experimental line LG82-8379. BSR 101 has nine of 10 major ancestral lines contributing to the commercial gene pool of North America, while LG82-8379 was selected from a cross between PI 68508 and FC 04007B. The F5–derived lines, divided into three sets based on maturity, were evaluated for 145 polymorphic simple sequence repeat (SSR) marker loci and for seed yield and other agronomic traits in 12 environments. Fifteen quantitative trait loci (QTL) were significantly [P < 0.05, likelihood of odds (LOD) > 2.5] associated with seed yield in at least one set with two significant across all sets. For nine of the yield QTL, the LG82-8379 alleles were associated with yield increases of 1.7 to 5.4% while the BSR 101 alleles increased yield 2.4 to 4.4% at six yield QTL. Four yield QTL were associated with significant changes in R8, eight with plant height, and three with seed protein concentration. Additional QTL were identified for R8, plant height, lodging, and seed protein and oil concentration. These results indicate that soybean PIs have the genetic potential for improving seed yield of U.S. soybean cultivars.