Detection and Validation of Agronomic and Seed Quality Quantitative Trait Loci in Soybean

Catherine Nyaguthii Nyinyi, University of Tennessee, Knoxville

Abstract

Soybean seed quality and agronomic traits are important commercially. Agronomic traits such as yield, plant height, lodging, and adapted maturity have been the primary focus of breeders for many years. Seed quality traits are also important as they affect the market price of soybean. Higher protein soybean historically is valued more per unit. It is the goal of plant breeders therefore to simultaneously improve seed quality and agronomic traits. Seed quality and agronomic traits are quantitative traits whose inheritance is governed by many genes, and whose expression is subject to environmental variation. Furthermore, negative correlations between yield and protein, and protein and oil make it even more difficult to select for these traits. Molecular breeding tools such as quantitative trait loci (QTL) can provide breeders with a more direct method of selection for traits at the molecular level. QTL can however be misleading as they are subject to type I and type II errors. QTL validation studies are essential to marker assisted programs as they negate the need for individual breeders to validate every QTL of interest. The purpose of this study was to validate previously reported seed quality and agronomic trait QTL in an independent population derived from an Essex x Williams 82 cross. We were able to validate QTL for all traits and detected novel QTL that may be useful to breeders.