APROARCH TO RICE BACTERIAL BLIGHT RESISTANCE THROUGH MOLECULAR GENETICS

利用RFLP和RAPD标记对水稻近等基因系和F_2群体的抗细菌基因Xa-1、Xa-3、Xa-4、Xa-5、Xa-10和Xa-11进行了标记。Xa-1与多个RFLP和RAPD标记连锁，图距小于5cM; Xa-3和Xa-4与同一RFLP标记连锁，为紧密连锁或等位。Xa-10与部分RFLP和RAPD标记连锁。本研究还发现了与xa-5和Xa-11连锁的RAPD标记，这些RFLP和RAPD标记可用于选育白叶枯病抗性基因的组合系，并将重组自交系作为RFLP/RAPD标记的永久定位群体，用于白叶枯病的数量抗性分析。利用RI群体构建的RFLP/RAPD标记图谱覆盖约1090 cM，包含114个RFLP位点和26个RAPD位点。初步鉴定了3个影响数量抗性的基因座。

Genes for bacterial resistance of rice, Xa-1, Xa-3, Xa-4, xa-5, Xa-10 and Xa-11, were tagged with several RFLP and RAPD markers using near-isogenic lines and F2 populations. Xa-1 linked to several RFLP and RAPD markers with map distances of less than 5cM.Xa-3 and Xa-4 that are closely linked or allelic, linked to the same RFLP markers. Xa-10 showed the linkage with some RFLP and RAPD markers. The RAPD markeres linked to xa-5 and Xa-11 were also found. These RFLP and RAPD markers were useful for developing the combined lines of the bacterial blight resisitance genes.We developed the recombinant inbred (RI) lines as a permanent mappinng population for RFLP/RAPD markers and used them to analyze the quantitative resistance to bacterial blight. The RFLP/RAPD land mark map constructed using the RI population covered approximately 1090 cM containg 114 RFLP loci and 26 RAPD loci. Three putative loci affecting the quantitative resistance were identified in the preliminary study.