【摘要】 稻白叶枯病和稻褐飞虱是水稻的主要病虫害,利用优良的抗性基因培育抗性基因聚合系对于防治稻白叶枯病和稻褐飞虱具有重要意义。本研究通过回交与分子标记辅助选择相结合的方法,将抗稻白叶枯病基因Xa23和抗稻褐飞虱基因Bph3分别导入主栽杂交水稻品种的保持系先B、天B、盟B、龙特甫B和桂B中。结果表明,获得稳定的单抗性基因导入系1436份和双抗性基因聚合系144份。人工接种鉴定结果显示,Xa23导入系和Xa23Bph3聚合系对抗稻白叶枯水平达到中抗和接近高抗的水平(1.1～3.0级),Bph3导入系和Xa23Bph3聚合系抗褐飞虱水平达中抗到抗的级别(3.2～4.0级)。农艺性状分析显示多数抗性基因聚合系的株高、剑叶长宽度、每穗粒数、结实率、千粒重等主要农艺性状与受体差异不显著,只有少数聚合系有1～2个性状的差异。SSR标记分析表明抗性基因聚合系的遗传背景回复率达89.6%～97.8%,等位性位点纯合度达95.6%～99.9%。初步证明本研究已成功地获得抗稻白叶枯病和稻褐飞虱基因的聚合系,这些抗性改良保持系具有良好的应用前景,并为建立完善的分子设计育种平台提供了重要育种材料基础。更多还原

【Abstract】 Plant brownhopper(BPH,caused by Nilaparvata lugens(Stl)) and bacterial leaf blight(BLB,caused by Xanthomonas campestris PV.Oryzae) are two of the major diseases in rice.To breed pyramided lines of the two disease-resistance genes are of great importance for the control of the two diseases.In this research,BLB and BPH resistance genes,Xa23 and Bph3,were accumulated into 5 maintainers of current main cultivated rice hybrids of Guangxi,Xian B,Tianfeng B,Meng B,Longtepu B and Gui B,via backcrossing together with molecular markerassisted selection(MAS).As a result,we obtained 1 436 single resistance gene-inserted lines and 144 double resistance gene-accumulated lines.Data from the inoculation with the BLB pathogen and BPH insect showed that the Xa23-inserted lines and Xa23Bph3 accumulated lines were moderately resistant or near highly resistant to the BLB with resistance scores 1.1～3.0,while the Bph3-inserted lines and Xa23Bph3 accumulated lines were moderately resistant to the BPH with resistance scores 3.2～4.0.Agronomic traits analysis reveal that there were no significant differences between most of the gene-accumulated lines and receptor parents in plant height,flag leaf length and breadth,grain number per panicle,filled grained rate and 1 000-grain weight,except one or two traits in a few accumulated lines.SSR analysis showed that the recovery rate of the resistance gene-accumulated lines was up to 89.6%～97.8% of the receptors,and their allelic homozygosity reached 95.6%～99.9%.The above results preliminary demonstrated the BPH and BLB resistance accumulated lines were successfully bred and these resistance rice maintainers were quite potential in developingnew promisingresistant hybrid varieties.This work would also provide a solid foundation in breeding material for the establishment of the molecular design breeding platform.更多还原