Characterization of a stable QTL for quality-related traits and its effects on yields in wheat (Triticum aestivum L.)

A total of 6 major stable QTLs and 59 pairwise epistatic eQTLs for quality-related traits were identified, and the candidate genes underlying qDt-KJ 4B, a novel major and stable QTL for dough tractility, were identified Wheat quality traits are usually negatively correlated with yield traits, but they affect the processing quality and nutritional value of wheat. Therefore, identifying more wheat quantitative trait loci (QTLs) and elucidating their genetic basis are essential for cultivating new high-quality and high-yielding wheat varieties. In this study, QTL analysis for five quality-related traits was performed on a recombinant inbred line (RIL) mapping population, KJ-RIL, derived from a cross between Kenong 9204 (KN9204) and Jing 411 (J411). A total of 6 major stable QTLs and 59 pairwise epistatic eQTLs (eQTLs) for dough tractility (DT), kernel hardness (KH), Zeleny sedimentation value (ZEL), water absorption (WAR) and wet gluten content (WGC) were identified in multiple environments. The genetic effects and additive pyramiding effects of the major and stable QTLs of qDt-KJ-4B on quality- and yield-related traits were characterized. The DT phenotypic values of the KJ-RILs increased with the number of favourable QTLs. BAB (only qDt-KJ-5D did not harbour favourable alleles) and BBA (only qDt-KJ-4A did not harbour favourable alleles) were the best combination for improving both the quality and yield potential of qDt-KJ-4B, qDt-KJ-4A and qDt-KJ-5D. The candidate genes underlying qDt-KJ-4B were predicted on the basis of multiomics data, with TraesKN4B01HG03930 and TraesKN4B01HG03950 as the most likely candidate genes. Overall, our results are helpful for elucidating the genetic relationships between quality- and yield-related traits and will aid in future development of new high-quality and high-yield wheat varieties to meet diverse consumption needs.