利用分子标记辅助选择育种(MAS)技术改良水稻恢复系粤恢826

Improving rice restorer line Yuehui 826 by marker-assisted selection(MSA)breeding technology

【目的】改良杂交稻恢复系粤恢826,以提高其稻瘟病和白叶枯病抗性,改良米质,为选育抗病、优质的杂交稻组合提供良好亲本材料。【方法】以含稻瘟病抗性基因Pi1和Pi2、白叶枯病抗病基因Xa23及蜡质基因Wx的中间材料Z1103为供体亲本,杂交水稻强恢复系粤恢826为受体亲本,利用分子标记辅助选择(MAS)技术和系谱选育方法,聚合4个外源基因以改良粤恢826的抗病性和米质,并进行稻瘟病和白叶枯病抗性及米质鉴定。【结果】经SSR分子标记检测、田间抗病性及米质鉴定,获得以粤恢826为遗传背景且含有目标基因的6个改良株系,通过农艺性状筛选与恢复力测试,优选到一个含有Pi1、Xa23和Wx基因的纯合株系,其恢复力好,农艺性状优良,2014年早造定名为粤恢88,其田间鉴定稻瘟病抗性3级,白叶枯病抗性1级,米质为软米。2014年晚造与两系不育系Y58S配制杂交稻组合Y两优88,其在品比试验中产量达6543 kg/ha,比对照深两优58香油占增产4.97%,未达显著水平(P>0.05),且抗稻瘟病,中抗白叶枯病,米质鉴定为国优3级和省优3级。【结论】MAS技术可有效聚合多基因(Pi1、Xa23和Wx基因),使粤恢826的稻瘟病和白叶枯病抗性及米质明显改良,获得抗稻瘟病、高抗白叶枯病、米质为软米的新恢复系粤恢88,为选育抗病优质的杂交稻组合提供良好亲本材料。

【Objective】Hybrid rice restorer line Yuehui826was improved to increase its resistance to rice blast and bacterial blight and enhance the rice quality in order to provide parent for hybrid rice combination with disease resistance.【Method】Material Z1103with rice blast resistant genes Pi1and Pi2,bacterial blight resistant genes Xa23and waxy gene Wx was donor parent,and hybrid rice restorer line Yuehui826was receptor parent.Molecular marker assisted selection technique and pedigree breeding were combined to improve disease resistance and rice quality of Yuehui826with four exogenous genes.The resistance to rice blast and bacterial blight,and rice quality were also detected.【Result】Through SSR molecular marker detection,rice quality analysis and field resistance identification,six improved inbred lines with Yuehui826as genetic background containing target genes were obtained.Through the further agronomic traits screening and restoring ability test,a soft rice strain containing genes Pi1,Xa23and Wx was selected and named Yuehui88in the early season of2014.Its restoring ability and agronomic traits were excellent.Its identified resistance to rice blast was grade3and bacterial blight grade1in field.In the late season of2014,Yuehui88crossed with two-line sterility line Y58S and obtained hybrid rice combination Y Liangyou88,which was resistant to rice blast and moderately resistant to bacterial blight.Its yield in trial reached6543t/ha,increased by4.97%compared with control Shenliangyou58xiangyouzhan,but the difference was insignificant(P>0.05).The rice quality was identified as national quality grade3and provincial quality grade3.【Conclusion】MAS technology can effectively realize multi-gene polymerization(genes Pi1,Xa23and Wx),improve resistance of Yuehui826to rice blast and bacterial blight and optimize rice quality.Moreover,the new restorer Yuehui88is obtained to provide parent materials for quality hybrid combination which are resistant to diseases.Yuehui88is soft rice with resistance to rice blast and strong resistance to bacterial blight.