小麦白粉病成株抗性和抗倒伏性及穗下节长度的QTL定位

QTL Mapping for Adult-Plant Resistance to Powdery Mildew,Lodging Resistance and Internode Length below Spike in Wheat

由小麦品种花培3号和豫麦57杂交获得了DH群体168个株系,利用305个SSR标记对白粉病成株抗性、抗倒伏性和穗下节长度进行了QTL定位研究。DH群体及两亲本于2005年和2006年种植于山东泰安,2006年种于安徽宿州。利用基于混合线性模型的QTLNetwork2.0软件,共检测到12个加性效应位点和10对上位效应位点。在4D染色体上控制白粉病成株抗性的qApr4D,贡献率为20.0%,在各环境中稳定表达,其抗病等位基因来源于抗病亲本豫麦57;在7D染色体上控制小麦穗下节长度的qIlbs7D,贡献率为12.9%,在各环境中稳定表达。加性效应和上位效应对小麦白粉病成株抗性、抗倒伏性和穗下节长度的遗传起重要作用,并且基因与环境常常具有互作效应。以上两个QTL可分别用于小麦白粉病成株抗性和穗下节长度的分子标记辅助选择。

Powdery mildew （Erysiphe graminis f. sp. tritici Em. Marchal.） and lodging cause great yield loss in wheat （Triticum aestivum L.） production. Adult-plant resistance （APR） is crucial in wheat breeding for permanent resistance to powdery mildew. Internode length below the spike （ILBS） is an important trait associated with lodging resistance （LDR） in wheat, however, the quantitative trait loci （QTLs） for ILBS have not been reported. In the present study, a set of 168 doubled haploid （DH） lines derived from the cross between Huapei 3 and Yumai 57 were used to detect QTLs associated with APR to powdery mildew, LDR, and ILBS with 305 SSR markers covering the whole wheat genome. The DH population and the parents were evaluated for APR to powdery mildew, LDR, and ILBS in 2005 and 2006 cropping seasons in Tai＇an, Shandong province and in 2006 cropping season in Suzhou, Anhui province. QTL analyses were performed using the software of QTLNetwork version 2.0 based on the mixed linear model. A total of 12 additive QTLs and l0 pairs of epistatic QTLs were detected for APR to powdery mildew, LDR, and ILBS. One QTL qApr4D, donated by Yumai 57, was detected for APR to powdery mildew on chromosome 4D with increased resistance effect, accounting for 20.0% of the phenotypic variances without additive × environment （AE） interactions. Another QTL qIlbs7D for ILBS was identified on chromosome 7D, explaining 12.9% of the phenotypic variances without AE interactions. The results indicate both additive effects and epistatic effects are important genetic bases for APR to powdery mildew, LDR, and ILBS, which are also sometimes subjected to environmental modifications. The two QTLs, qApr4D and qllbs7D, are useful for molecular marker-assisted selection in breeding for APR to powdery mildew and ILBS, respectively.