普通小麦白粉病成株抗性的QTL分析

 【目的】以普通小麦加倍单倍体（doubled haploid，DH）群体（旱选10号×鲁麦14）的150个株系为材料，鉴定其白粉病成株抗性并进行QTL定位，以期发掘具有显著效应以及不同环境中稳定表达的主效QTL，为改良小麦白粉病成株抗性提供理论依据及分子标记。【方法】运用基于混合线性模型的复合区间作图法，对DH群体在4种单一环境条件下及基因型与环境互作情况下白粉病成株抗性进行QTL定位。【结果】4种单一环境条件下共检测到15个控制白粉病成株抗性的加性效应QTL，对白粉病成株抗性表型变异的贡献率为3.8%～21.0%；考虑基因型与环境互作的情况下检测到9个加性QTL，分别与单一环境下检测到的加性QTL位于相同的标记区间，位于染色体2A、2B、3A、5A、5B、6B、7A、7B和7D上。4种单一环境下检测到17对上位性效应QTL，对白粉病成株抗性表型变异的贡献率为1.1%～28.4%；考虑基因型与环境互作情况下检测到19对上位性QTL，其中7对与单一环境下的上位性QTL位于相同的标记区间。控制白粉病成株抗性的QTL来自于双亲，DH群体中有白粉病成株抗性超亲的株系存在。【结论】白粉病成株抗性受加性和上位性QTL的共同作用；在基因型与4种环境互作情况下检测到的QTL中，分别有9个加性QTL和7对上位性QTL与单一环境下的QTL位于相同的标记区间，这些在不同环境条件下重复出现的QTL具有较好的稳定性；通过分子标记辅助选择等方法重组、聚合目标QTL，将能够选育出白粉病抗性强的小麦品种。

QTL Mapping for Adult-Plant Resistance to Powdery Mildew in Common Wheat

Abstract: 【Objective】In this study, a doubled haploid (DH) population with 150 lines, which was derived from the cross of two Chinese common wheat cultivars Hanxuan 10 and Lumai 14, was used as the plant material to identify the adult-plant resistance to powdery mildew (APRPM) and carry out Quantitative trait loci (QTL) analysis. The purpose was to find some essential QTLs with stable and remarkable effects for marker-assisted selection for improving powdery mildew resistance in wheat breeding program.【Method】The mixed-model-based composite interval mapping method was employed to identify the quantitative trait loci (QTL) for APRPM in four single environments and across four environments.【Result】A total of 15 additive QTLs were detected in four single environments, explaining 3.8%～21.0% phenotype variance. Across four environments, 9 additive QTLs were detected. They were at the same flanking marker interval with the additive QTLs detected in four single environments, located on chromosome 2A, 2B, 3A, 5A, 5B, 6B, 7A, 7B and 7D, respectively. And 17 pairs of epistatic QTLs explaining 1.1%～28.4% phenotype variance were identified in four single environments. Across four environments, 19 pairs of epistatic QTLs were detected. Among them, 7 pairs QTLs shared the same flanking marker interval with QTLs identified in four single environments. The allelic contribution to the APRPM QTLs came from both parents. Some DH lines were more resistant to the adult-plant powdery mildew than their parents【Conclusion】Our results showed that the APRPM was controlled by both additive and epistatic QTLs. The overlapped QTLs were stable in different environments. Therefore, adult-plant resistance to powdery mildew can be improved in wheat breeding program by recombining and pyramiding target QTLs using marker assisted selection.