Analysis of Quantitative Trait Loci (QTL) for Grain Yield and Agronomic Traits in Wheat (Triticum aestivum L.) Under Normal and Salt-Stress Conditions

摘要

A 179-recombinant inbred line (RIL) population derived from the cross Attila/Kauz x Karchia were evaluated in 10 environments (5 salt-affected and 5 non-salt-affected fields) to identify the quantitative trait loci (QTLs) for grain yield, yield components and agronomic traits. A genetic linkage map included 118 loci, which were composed of 10 microsatellite (simple sequence repeat (SSR)) and 108 diversity arrays technology (DArT) markers, on 9 chromosomes (1A, 1B, 2A, 2B, 3B, 5B, 5D, 6B, 7A). The QTL analysis for each trait was carried out for the data in individual environments. In total, 29 repeatable QTLs were identified across a combination of 10 environments on 9 chromosomes for the 10 evaluated traits, of which 11, 8 and 10 QTLs were associated exclusively with control, saline and both conditions, respectively. Over half of the QTLs for different traits were located on chromosomes 2A, 2B, 3B and 6B. Five repeatable grain yield (GY) QTLs were detected on chromosomes 2B, 5D, 6B and 7A. Among them, the QTL for GY QTLs on chromosomes 2B and 6B was co-located with the QTLs controlling grain number per ear (GNE) and grain weight per ear (GWE). Our results suggest that it may be possible to improve yield stability by combining GY QTLs expressed under contrasting yielding environments. In particular, combining the Karchia alleles on 5D and 6B (QTLs for GY on 5D and 6B accounted for 12.4 and 10.5 % of phenotypic variation explained (PVE) under salt stress, respectively) into wheat genetic backgrounds may increase the yield stability, especially, under saline environments.