【摘要】 本研究为了分离海南省白叶枯病菌优势生理小种及确定其致病力,首先利用6个携单一抗病基因(Xa3,Xa4,xa5,Xa13,Xa21和Xa23)的水稻白叶枯病鉴别品种及对照品种(IR24),对海南省18个市县采集的25份水稻白叶枯病叶浸泡出的菌株进行初步的致病力分析,结果表明,海南水稻白叶枯病叶浸泡出的菌株可以分为6个致病类型,其中2号致病类型是优势致病类型且对xa5、Xa23基因以外的其他基因都致病,为致病力最强的类型。接着从优势致病类型病叶中分离纯化得到单克隆菌株,并利用上述7个鉴别品种及其他8个携单一抗性基因的近等基因系(Xa1,Xa2,Xa7,Xa8,Xa10,Xa11,Xa14,Xa27)对其致病力进行进一步分析。结果表明,单克隆菌株在鉴别寄主上的致病力与病叶渗出菌株的致病力一致,只有xa5、Xa7、Xa23、Xa27基因对其具有抗性。本研究建立了一套简易、快速的分离鉴定水稻白叶枯病优势生理小种的方法,将为海南乃至全国白叶枯病抗病育种提供鉴别菌株与抗病效果好的候选基因。更多还原

【Abstract】 25 Xanthomonas oryzae pv.oryzae(Xoo) of soaking mixture from rice blight leaves collected in 18 cities of Hainan province,were identified by a check variety IR24 and 6 near-isogenic lines harboring a single resistance gene Xa3, Xa4, xa5, Xa13, Xa21 or Xa23, respectively. The results showed that the pathotypes of Xoo strains in Hainan were classified into 6 groups. The pathotype of no.2 was the predominant and highest virulent race, which has virulence to genes Xa3, Xa4, Xa13, Xa21 except xa5 and Xa23. The single isolates from disease leaves infected by the predominant strains was further evaluated on 7 near-isogenic lines mentioned above, and other 8 near-isogenic lines(Xa1, Xa2, Xa7, Xa8, Xa10, Xa11, Xa14, Xa27). The results indicated that the pathotype of single isolate was same as no. 2 pathotype, and genes xa5, Xa7, Xa23 and Xa27 resisted it. The study builds on a set of a simple and rapid method to isolate the predominant race of Xoo, and provides the standard strain of Xoo and optimal genes for breeding and improving of resistance to Xoo.更多还原