母本繁殖是杂种优势利用的重要基础环节。母本繁殖搞得不好,不仅降低制种田的产量和杂种质量,而且影响大田生产中杂种的增产幅度。国内已育成的40多个核不育材料,一类是全不育型,如延A、水A等,其不育性受一对隐性核基因控制,不育特征明显,败育发生时期较早,花药瘦小。据我们镜检结果,多为无花粉型,败育整齐,不育性稳定,极少有半不育株出现。不育度在99％以上,不育株率却只 Maternal reproduction is an important basis for the utilization of heterosis. Maternal reproduction is not done well, not only to reduce the production of grain and hybrids quality, but also affect the production of hybrids in the field of yield increase. There are more than 40 nuclear sterile materials that have been bred in China. One is the all-sterile type, such as Yan A and A, whose sterility is controlled by a pair of recessive nuclear genes. The characteristics of sterility are obvious, Earlier, anthers skinny. According to our microscopic examination results, mostly pollen-type, sterile and neat, sterile and stable, very few semi-sterile plants appear. Sterility in more than 99%, sterile plant rate only