中国杂交水稻白叶枯病抗性的遗传改良

 20世纪80年代，中国杂交水稻抗白叶枯病育种进展迅速。在大面积种植的籼型三系和两系杂交稻中主要应用白叶枯病抗性基因Xa4，白叶枯病在生产中几乎“销声匿迹”了20年。但近年来，此病害却在长江流域一些种植新组合的稻田里又爆发了。什么原因引起它再度流行？品种的抗性是否还有效？抗病育种是否还是水稻改良的主要目标之一？通过哪些途径才能更有效地利用抗病基因培育出更为持久的抗性品种？为回答这些问题，就我国杂交水稻对白叶枯病抗性的改良，寄主与病菌群体的互动演变效应进行了分析，讨论了拓宽抗性遗传基础、白叶枯病菌毒性群体结构、基因轮换、合理利用基因等问题。 在采用了包括传统方法、分子标记辅助选择和转基因技术的综合策略后，杂交水稻抗白叶枯病育种研究将出现新的局面。

Genetics and Improvement of Resistance to Bacterial Blight in Hybrid Rice in China in China

Since the 1980s, hybrid rice breeding for resistance to bacterial blight in China has been rapidly progressing. The gene Xa4 was mainly used in three line indica hybrid and two line hybrid rice grown in a large area. The disease has been seen “quiet” for 20 years in China, yet in recent years it has gradually emerged prevalently in fields planted with newly released rice varieties in the Yangtze River Valley. This situation for scientists inevitably raised several questions: what causes the resurgence? Is the resistance of variety still effective? And/or is resistance breeding still one of the main objectives of rice improvement? What approach do we take on resistance breeding so that the resistance will be more durable, and the resistance gene will be used more efficiently? A combined strategy composed of traditional method, molecular marker assisted selection, and transgenic technology should bring a new era to the bacterial blight resistance hybrid rice breeding program. The review also briefly discusses and deliberates on issues related to the broadening of bacterial blight resistance, and suitable utilization of resistance genes, alternation planting of available resistance genes, and introduces the virulent populations of the bacterial blight pathogen in China even in Asia.