分子标记辅助选择Xa23基因改良早稻恢复系白叶枯病抗性研究

Study on Enhancing Bacterial Blight Resistance of Hybrid Rice Restorer Lines through Marker Assisted Selection of the Xa23 Gene

利用常规杂交和回交的方法,并通过分子标记辅助选择技术,以携带抗白叶枯病基因Xa23水稻材料IRBBL23为供体材料,以优良早稻恢复系东南恢012的为受体材料,在低世代利用与Xa23基因紧密连锁的分子标记C189在分离群体中进行分子标记辅助选择,在高代稳定株系中采用苗期群体鉴定技术,最终获得一系列目标基因纯合且农艺性状优良的早熟恢复系材料。通过白叶枯病菌株的专化强毒菌系P6对8份材料进行田间接种鉴定,筛选出7份抗白叶枯病的恢复系材料,并对这些株系的主要农艺性状进行了调查和分析。结果表明利用与Xa23基因紧密连锁的分子标记C189开展抗白叶枯病分子标记辅助育种是一种简便、有效的途径。

The bacterial blight is one of the major diseases in rice.One effective control measure for bacterial blight is to breed resistance cultivars through molecular marker closely linked to the resistance genes.The rice bacterial blight resistance gene Xa23,carried by the donor parent IRBB23,was introduced into the restorer line Dongnanhui 012＇by regular and back crossing and molecular（marker assisted selection.This research was carried out in low generation without resistance using molecular marker assisted selection with marker C189 closely linked to Xa23 gene,and in high and stable strains using seedling population identification technology.A series of precocious restore lines with homozygous target genes Xa23 and stable good agronomic characters were obtained through testing the flanking marker C189.The eight lines were subject to bacterial blight disease inoculation at the booting stages,and results showed that seven lines were resistant to the most destructive Xoostrain PXO 99（P6）.Meanwhile,we also analyzed the main agronomic traits of the seven homozygous lines.These results clearly suggested that the marker C189 linked to Xa23 could be conveniently and effectively used in the bacterial blight resistance breeding programs of rice.