Novel quantitative trait loci for forage quality traits in a cross between PI 483463 and ‘hutcheson’ in soybean

Soybean [Glycine max (L.) Merr.] is one of the most important forage crops in the world. This study aimed to map quantitative trait loci (QTL) for crude protein (CP), crude fat (CF), neutral detergent fiber (NDF) and acid detergent fiber (ADF) in soybean. A set of 188 recombinant inbred lines (RILs) derived from a cross between PI 483463 and ‘Hutcheson’ were grown for three consecutive years. Plants of each RIL were harvested at the R6 stage and quality traits were measured using near-infrared reflectance spectroscopy (NIRS). The variance components of genotype, environment, and genotype × environment (G × E) interactions were highly significant for all quality traits in the RIL population. Significant positive and negative correlations were observed among forage quality traits. Composite interval mapping analysis identified six QTL for CP, two for CF, six for NDF, and two for ADF. Individual QTL explained phenotypic variation in the range 7.04 to 26.46% for CP, 6.62 to 29.33% for CF, 5.79 to 28.19% for NDF, and 7.66 to 41.72% for ADF. Coincident QTL for all traits were observed on chromosome 19. Novel QTL identified in this study may be useful for developing soybean genotypes with improved forage quality.