Identification of solvent retention capacity quantitative trait loci by combined linkage and association mapping in wheat (Triticum aestivum L.)

Solvent retention capacity (SRC) is an important tool for assessing wheat quality by estimating the biochemical characteristics of flour components. Although it has been widely used in wheat breeding programs, its genetic architecture is still poorly understood. Hence, the objective of this study was to find quantitative trait loci (QTLs) associated with four SRC traits, namely sucrose SRC, sodium carbonate SRC, water SRC and lactic acid SRC, in a recombinant inbred line population consisting of 173 lines descended from Shannong 01-35/Gaocheng 9411 and an association panel of 205 wheat varieties. The 90K single nucleotide polymorphism array was used to genotype both populations. SRC was primarily influenced by genotype, with broad-sense heritability (H-2) ranging from 59.72% to 80.76%. Linkage mapping revealed seven major QTLs on chromosomes 1B, 4B, 5B, and 6B. Among them, QSc1B.6-27 was repeatedly identified in two different environments, with a 14.7% phenotypic variance explained value. Additionally, 24 significant QTLs, consisting of 57 marker-trait associations, were identified using association mapping across four environments. Nineteen of them explained more than 10.0% of the phenotypic variance, with QSU6A.141 explaining the most (20.1%). Two common chromosomal regions were discovered when combining the two mapping populations. These regions were located between IACX5803 and BS00067000_51 on chromosome 1B and between IACX557 and CAP11_c3631_75 on chromosome 4B, respectively. In addition, four candidate genes associated with wheat SRC were identified. These findings shed light on the complex genetic mechanisms underlying wheat SRC and may help to genetically enhance wheat quality.