小麦品种扬麦16赤霉病抗扩展QTL定位及分析

扬麦系列品种赤霉病抗性在世界范围内得到重视,但其抗性遗传机制尚不清楚。扬麦16是近年来大面积推广的抗赤霉病品种,本研究以扬麦16与中麦895杂交构建的174个双单倍体(doublehaploidlines,DH)系为材料,于2017—2019年连续3年对该群体采用单花滴注进行赤霉病抗扩展鉴定。利用660KSNP芯片构建高密度遗传图谱,共检测到6个抗性QTL,分别位于2DL、3BL、4BS、4DS、5BL和6AS染色体上。除4BS位点外,其他5个抗性等位基因均来源于扬麦16。QFhb.yaas-4DS和QFhb.yaas-6AS均在多年被检测到,可解释8.8%～15.0%的表型变异;QFhb.yaas-2DL、QFhb.yaas-3BL仅在1年被检测到,分别解释10.5%和14.7%的表型变异;QFhb.yaas-5BL和来源于中麦895的QFhb.yaas-4BS仅在1年被检测到且效应仅为6.4%和8.3%。QTL效应分析结果表明,相较于单个位点,多个抗性QTL的聚合可显著降低赤霉病严重度。扬麦16抗赤霉病QTL将为揭示扬麦品种抗性遗传机制及开发相应分子标记奠定基础。

Mapping and genetic analysis of QTLs for Fusarium head blight resistance to disease spread in Yangmai 16

Fusarium head blight (FHB) resistance of Yangmai wheat cultivars has been paid much attention, but the underlying genetic mechanism is unclear. In recent years, Yangmai 16 is a predominant wheat cultivar durably resistant to FHB in production. A population of 174 double haploid lines (DH) produced by crossing Yangmai 16 (YM16) with the susceptible cultivar Zhongmai 895 (ZM895) was evaluated for FHB response using point inoculation from 2017 to 2019. The DH population was genotyped with wheat 660K SNP array and a high-density genetic map was constructed. Six resistance QTLs were detected, and among them, five were from the resistant parent Yangmai 16 and one from Zhongmai 895. QFhb.yaas-4DS and QFhb.yaas-6AS were detected at least in two years, explaining 8.8% to 15.0% of the phenotypic variances, respectively. QFhb.yaas-2DL and QFhb.yaas-3BL were detected only in one year, accounting for 10.5% and 14.7% of the phenotypic variances. QFhb.yaas-5BL and QFhb.yaas-4BS were detected in one year, too, accounting for 6.4% and 8.3% of the phenotypic variances, respectively. Pyramiding of multiple resistant loci with large effects (>10%) is an effective approach to increase FHB resistance. The QTLs identified from Yangmai 16 in the present study will provide a starting point for genetic studies of other Yangmai cultivars, and the QTLs closely linked to markers will be useful for marker-assisted selection in wheat FHB improvement.