自70年代推广杂交稻以来,制种面积不断扩大(每年近200万亩),致使稻粒黑粉病在制种母本上的发生连年加重。据调查,我市的所有制种和不育系繁殖田块均有不同程度地发生,常年发病率在10％～20％,重者达50％以上,严重影响了制种的产量和质量,是当前杂交稻制种上亟待解决的重要问题。造成不育系病害严重的原因有很多。 Since the promotion of hybrid rice in the 1970s, the area for seed production has expanded continuously (nearly 2 million mu per year), causing the occurrence of rice grain smut in successive years. According to the survey, all the species of the city and the breeding line of the sterile line all occur in varying degrees, with the annual incidence rate of 10% -20% and the weight of more than 50%, seriously affecting the yield and quality of seed production. The current important problem to be solved on hybrid rice seed production. There are many reasons for the serious disease of CMS.