Gao Dong-Ying, Xu Zhi-Gang, Chen Zhi-Yi, Sun Li-Hua, Sun Qi-Ming, Lu Fan, Hu Bai-Shi, Liu Yong-Feng
Institute of Agricultural Genetics and Phsiology, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
Yi Chuan Xue Bao. 2002 Feb;29(2):138-43.
Using the mature embryo of a susceptible rice variety Minghui 63 as the explant, we have obtained a somaclonal mutant HX-3 through selection in vitro, which has showed resistance to bacterial blight. In 8 successive years, the resistance of R1 to R9 generations of HX-3 was identified by ZJ173, a typical bacterial blight strain in Yangtsu River valley, and the results showed that the resistance of HX-3 was stable and heritable. Genetic analysis also indicated that the resistance of HX-3 to bacterial blight was under a dominant gene controlling. Using 32 bacterial blight strains collected in China, Philippines and Japan, the resistance spectrum of HX-3 and other 13 testers with different major dominant resistance genes were tested. Results of 2 years (1999-2000) experiment showed that HX-3 had a broad resistance spectrum, which seemed to be different with those of the other dominant resistance genes identified. Allelic tests were also conducted by crossing HX-3 with IRBB4, IRBB7, CBB12 and IRBB21, and the F2 populations of each of the 4 crosses demonstrated resistant and susceptible plant segregation, indicating that the resistance gene in HX-3 different from Xa-4, Xa-7, Xa-12 and Xa-21. All these results proved that there was a new resistance gene in HX-3. We have designated the new gene as Xa-25(t).
以感病水稻品种明恢63的成熟胚为外植体，通过离体筛选获得了对白叶枯病具有抗性的体细胞克隆突变体HX-3。连续8年用长江流域典型白叶枯病菌株ZJ173对HX-3的R1至R9代抗性进行鉴定，结果表明HX-3的抗性稳定且可遗传。遗传分析还表明，HX-3对白叶枯病的抗性受一个显性基因控制。利用在中国、菲律宾和日本收集的32个白叶枯病菌株，对HX-3和其他13个具有不同主要显性抗性基因的测试品种的抗性谱进行了检测。1999 - 2000年两年的试验结果表明，HX-3具有较宽的抗性谱，这似乎与已鉴定的其他显性抗性基因不同。通过将HX-3与IRBB4、IRBB7、CBB12和IRBB21杂交进行等位性测验，4个杂交组合的F2群体均表现出抗性和感病植株分离，表明HX-3中的抗性基因与Xa-4、Xa-7、Xa-12和Xa-21不同。所有这些结果证明HX-3中存在一个新的抗性基因。我们已将该新基因命名为Xa-25(t)。
