Phenotypic performance and associated QTL of ‘Peace’ × ‘CDC Stanley’ mapping population under conventional and organic management systems

Abstract

AbstractIdentification of consistent QTL in both conventional and organic management systems is a prerequisite for improving spring wheat (Triticum aestivum) through marker‐assisted selection. The objectives of the present study were to continue investigating the effect of management systems on agronomic and end‐use quality traits, and map associated quantitative trait loci (QTL) in a hard red spring wheat population. We evaluated 165 recombinant inbred lines derived from ‘Peace’ × ‘CDC Stanley’ for nine agronomic and end‐use quality traits under conventional and organic management systems for 2 yr and genotyped them with the wheat 90K iSelect array. Using inclusive composite interval mapping on phenotypic data across two environments per management and the International Wheat Genome Sequence Consortium (IWGSC) RefSeq v2.0 physical map of 1,058 informative single nucleotide polymorphisms, we uncovered 32 QTL (17 under conventional and 15 under organic) associated with nine traits of which five QTL were common in both managements. The remaining QTL were specific either to the conventional (12) or organic (10) managements. Each QTL explained from 1.2 to 19.2% and together accounted for 3.0 to 28.4% and 3.3 to 21.9% of the total phenotypic variance of each trait evaluated under conventional and organic management systems, respectively. We found three coincident genomic regions on chromosomes 1B, 3B, and 4B associated with two and three traits. All QTL identified in the present study were not reported in any of our previous mapping populations and would provide more data to wheat researchers conducting similar studies under conventional and organic management systems.