分子标记辅助选择改良杂交水稻组合Q优6号的白叶枯病抗性

Improvement of Bacterial Blight Resistance of Hybrid Rice Q-You 6 by Molecular Marker-Assisted Selection

杂交水稻组合Q优6号是长江中下游稻区大面积推广的中熟三系杂交中稻组合,对白叶枯病抗性较差。本研究采用杂交、回交和分子标记辅助选择技术,将广谱抗性基因Xa23渗入到恢复系R1005中,综合农艺性状选择和Xa23基因分子标记选择,获得1份具有Xa23基因的优良株系CY11701-4。对该株系和以Q2A为母本配制的组合进行白叶枯病抗性鉴定,结果表明CY11701-4及Q2A/CY11701-4对接种的7个菌株(PXO61,PXO99,ZHE173,GD1358,FuJ,YN24和HeN11)均表现高抗水平。经主要农艺性状、产量和主要稻米品质指标测定分析,CY11701-4与R1005没有显著差异,Q2A/CY11701-4与Q优6号主要农艺性状没有显著差异,播始历期缩短1.3 d,产量显著提高。

Q-You 6, a three-line hybrid rice variety planting in Yangtze River Basin, is susceptible to bacterial blight caused the yield losses. We introgressed a bacterial blight resistance gene Xa23 from JYQ9008 into the male parent R1005 of Q-You 6 by molecular marker assisted selection and phenotypic selection. One line, CY11701-4, carrying Xa23 gene under the R1005 background was developed and crossed with Q2A, the female parent of Q-You 6. The results showed that CY11701-4 and Q2A/CY11701-4 were resistant to seven Xoo strains, including PXO61, PXO99, ZHE173, GD1358, FuJ, YN24 and HeN11. The evaluation results of grain quality, yield and yield-related traits showed that CY11701-4 and Q2A/CY11701-4 were as similar to R1005 and Q-You 6, respectively.