Mapping Freezing Tolerance Quantitative Trait Loci in Bread Wheat (Triticum aestivum) using a Doubled Haploid Population

摘要

Exposure to cold conditions is a major abiotic stress affecting crop growth and productivity. Here, quantitative trait loci (QTLs) for antioxidant enzyme activity, ratio of free water to bound water (RFB), and malondialdehyde (MDA) content in six environments were identified using a doubled haploid wheat population derived from a cross between Huapei-3 and Yumai 57 wheat cultivars. These QTLs were analyed using an inclusive composite interval mapping approach. Consequently, 35 additive QTLs for specific traits were identified, including QRFB-2A-1, which was detected in three environments. Moreover, QPO - 2D-2 and QPOD-1B, which were associated with peroxidase activity, were detected in two environments, with QPOD-2D 2 responsible for more than 10% of the phenotypic variation. Additionally, QCAT-6D-2 on chromosome 6D explained 16.80% of the phenotypic variation, with the positive effect contributed by Huapei-3. Furthermore, eight additive QTLs for MDA content were detected on chromosomes 1A, 2B, 3A, 4B, 5B.2, 6B and 7B, including QMDA-6B between markers Xcfa2257 and Xcfd48, which was responsible for 20.21% of the phenotypic variation. By marker-assisted selection, the major QTLs detected in this study may be valuable for improving freezing tolerance in wheat.