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稻瘟病是水稻(Oryza sativa L.)三大病害之一,对水稻产量和品质造成了严重的影响。本研究利用优良恢复系R287与广谱抗稻瘟品种细麻线的BC3F1回交群体构建的分子标记遗传连锁图谱,并通过全生育期自然诱发稻瘟病进行抗性鉴定。结果显示,全基因组分析共定位到16个抗叶瘟和13个抗穗颈瘟相关的QTLs,所有抗性QTL均来源于细麻线。其中q BR3是位于第3染色体上同时控制水稻叶瘟和穗颈瘟抗性效应的QTL,其能够提高叶瘟抗性2个数量级和降低穗颈瘟发病率40%左右。q BR3对叶瘟和穗颈瘟的抗性LOD值分别为18.63和22.77,解释的表型变异率分别为21.20%和26.10%。通过对水稻已有稻瘟病抗性位点的定位结果分析,发现q BR3可能是一个新的广谱抗性QTL位点。本研究结果为稻瘟病抗性育种提供了新的基因资源。
Rice blast is one of the three diseases of rice (Oryza sativa L.), which has a serious impact on the yield and quality of rice. In this study, we constructed a molecular marker linkage map constructed by BC3F1 backcrossing population of elite restorer line R287 and a broad-spectrum resistant rice blast line, and identified the resistance by natural blast induced during the whole growth period. The results showed that QTLs related to leaf blast and 13 panicle blast resistant to leaf blast were mapped by genome-wide analysis. All QTLs were derived from fine twine. Among them, q BR3 is located on chromosome 3 and controls the resistance of rice leaf blast and panicle blast simultaneously. It can increase two orders of magnitude of leaf blast resistance and reduce the incidence of panicle blast about 40%. The resistance LOD values of q BR3 to leaf blast and panicle blast were 18.63 and 22.77, respectively. The explained phenotypic variation rates were 21.20% and 26.10% respectively. Through the analysis of rice blast resistance loci, q BR3 may be a new broad-spectrum resistant QTL locus. The results provided a new genetic resource for rice blast resistance breeding.