Characterization of a wheat stable QTL for spike length and its genetic effects on yield-related traits

Abstract

Abstract Spike length (SL) is one of the most important agronomic traits affecting yieldpotential and stability in wheat. In this study, a major stable quantitative trait locus (QTL) for SL, i.e., qSl-2B, was detected in multiple environments in a recombinant inbred line (RIL) mapping population derived from a cross between Kenong 9204 (KN9204) and Jing 411 (denoted as KJ-RIL). The qSl-2B QTL was mapped to the 60.06–73.06 Mb region on chromosome 2B and could be identified in multiple mapping populations. An InDel molecular marker in the target region was developed based on a sequence analysis of the two parents. To further clarify the breeding use potential of qSl-2B, we analyzed its genetic effects and breeding selection effect using both the KJ-RIL population and a natural mapping population, which consisted of 316 breeding varieties/advanced lines. The results showed that the qSl-2B alleles from KN9204 showed inconsistent genetic effects on SL in the two mapping populations. However, the qSl-2B alleles from KN9204 significantly increased grain yield per plant(GYPP) in both mapping populations. In China, a moderate selection utilization rate for qSl-2B was found in the Huanghuai winter wheat area and the selective utilization rate for qSl-2Bcontinues to increase. The above findings provided a foundation for the genetic improvement of wheat SL in the future via molecular breeding strategies.