Yang Zhuping, Gilbert Jeannie, Fedak George, Somers Daryl J
Agriculture and Agri-Food Canada, Cereal Research Centre, Winnipeg.
Genome. 2005 Apr;48(2):187-96. doi: 10.1139/g04-104.
Fusarium head blight (FHB) is one of the most important fungal wheat diseases worldwide. Understanding the genetics of FHB resistance is the key to facilitating the introgression of different FHB resistance genes into adapted wheat. The objectives of the present study were to detect and map quantitative trait loci (QTL) associated with FHB resistance genes and characterize the genetic components of the QTL in a doubled-haploid (DH) spring wheat population using both single-locus and two-locus analysis. A mapping population, consisting of 174 DH lines from the cross between DH181 (resistant) and AC Foremost (susceptible), was evaluated for type I resistance to initial infection during a 2-year period in spray-inoculated field trials, for Type II resistance to fungal spread within the spike in 3 greenhouse experiments using single-floret inoculation, and for resistance to kernel infection in a 2001 field trial. One-locus QTL analysis revealed 7 QTL for type I resistance on chromosome arms 2DS, 3AS, 3BS, 3BC (centromeric), 4DL, 5AS, and 6BS, 4 QTL for type II resistance on chromosomes 2DS, 3BS, 6BS, and 7BL, and 6 QTL for resistance to kernel infection on chromosomes 1DL, 2DS, 3BS, 3BC, 4DL, and 6BS. Two-locus QTL analysis detected 8 QTL with main effects and 4 additive by additive epistatic interactions for FHB resistance and identified novel FHB resistance genes for the first time on chromosomes 1DL, 4AL, and 4DL. Neither significant QTL by environment interactions nor epistatic QTL by environment interactions were found for either type I or type II resistance. The additive effects of QTL explained most of the phenotypic variance for FHB resistance. Marker-assisted selection for the favored alleles at multiple genomic regions appears to be a promising tool to accelerate the introgression and pyramiding of different FHB resistance genes into adapted wheat genetic backgrounds.
小麦赤霉病（FHB）是全球最重要的小麦真菌病害之一。了解抗小麦赤霉病的遗传学是促进将不同抗小麦赤霉病基因渗入适应性小麦品种的关键。本研究的目的是检测和定位与抗小麦赤霉病基因相关的数量性状位点（QTL），并使用单基因座和双基因座分析来表征双单倍体（DH）春小麦群体中QTL的遗传组成。一个由174个DH系组成的作图群体，来自DH181（抗病）和AC Foremost（感病）的杂交组合，在2年的喷雾接种田间试验中评估了对初始感染的I型抗性，在3次温室实验中使用单小花接种评估了对穗内真菌传播的II型抗性，并在2001年的田间试验中评估了对籽粒感染的抗性。单基因座QTL分析揭示了在染色体臂2DS、3AS、3BS、3BC（着丝粒）、4DL、5AS和6BS上有7个I型抗性QTL，在染色体2DS、3BS、6BS和7BL上有4个II型抗性QTL，在染色体1DL、2DS、3BS、3BC、4DL和6BS上有6个对籽粒感染抗性的QTL。双基因座QTL分析检测到8个具有主效应的QTL和4个FHB抗性的加性×加性上位性互作，并首次在染色体1DL、4AL和4DL上鉴定出新型FHB抗性基因。对于I型或II型抗性，均未发现显著的QTL×环境互作或上位性QTL×环境互作。QTL的加性效应解释了FHB抗性的大部分表型变异。在多个基因组区域对有利等位基因进行标记辅助选择似乎是一种有前途的工具，可加速将不同的FHB抗性基因渗入并聚合到适应性小麦遗传背景中。
