ARz×扬麦158群体对小麦抗赤霉病性的QTL分析

QTL Analysis of Fusarium Head Blight Resistance(FHB) in ARz ×Yangmai 158 Population

通过单粒传法构建了含130个家系的ARzx扬麦158F。重组自交系群体（RIL），并采用田间病圃自然发病和喷洒悬浮孢子液两种方法对该群体进行赤霉病田间抗性鉴定；利用SSR标记对群体中控制抗赤霉病性的QTL进行定位分析。结果表明：群体中各家系的病情指数在所有试验中都存在很大的变异，在2002年、2003年和2005年其变异幅度分别为20．0％-80．0％，10．6％-74．6％和33．2％-89．0％；不同年份间的病情指数具有中等程度的相关性，且都达到了极显著水平（P〈0．0005）；Xgwm114、Xgwm296、Xgwm111．2等15个SSR标记位点与群体抗赤霉病性显著相关，这些位点分别位于2DL、3BL和7DL等染色体上；经区间作图分析发现位于染色体7D上的Xwmc94-Xwmc273．2区间存在一个抗赤霉病QTL，它在3年试验中的LOD值分别为1．5、2．6和2．0，可解释病情指数变异率的5．8％、8．7％和6．7％，Xgwm114是与该抗赤霉病QTL紧密连锁的标记位点，位于该抗性QTL的峰佰及域．

A recombinant inbred line （RIL） population was developed from a cross between wheat varieties ARz and Yangmai 158 by single-seed descent was developed. The RIL population was evaluated in the field for Fusarium head blight （FHB） resistance by spraying mixed conidial suspension at anthesis. Disease index of the RIL population varied in the trials,ranging from 20.0% to 80.0%, 10.6% to 74. 6% and 33.2% to 89. 0% in 2002, 2003 and 2005, respectively. The correlation coefficients of disease indices of RIL population between three years were significantly different （ P 〈 0.000 5）. Fifteen loci genotyped with simple sequence repeat（SSR） markers in the RIL population were associated with wheat scab resistance significantly. Among them,Xgwm 114 ,Xgwm 296 and Xgwm 111. 2 located on chromosomes 2DL,3BL and 7DL, respectively . A QTL between Xwmc 9 4 - Xwmc 2 73. 2 interval was found to associate with FHB resistance in three years trials by interval mapping （IM）, with LOD scores of 1.5, 2.6 and 2.0, explaining 5.8%, 8.7% and 6.7% of the phenotypic variance in 2002, 2003 and 2005, respectively. Xgwm114 was the closest marker locus linked to the QTL and located at the peak region of its interval.