一个玉米细胞质雄性不育系的鉴定及遗传分析

【目的】阐明新育成的雄性不育系农系928cms-Q1261的胞质类型、败育时期和遗传机制，为其育种应用提供依据。【方法】将不育系在不同年份、不同地点种植，鉴定育性表现，通过测交、姊妹交、反交对不育性的遗传进行分析，利用特异引物进行PCR扩增鉴定胞质类型，通过石蜡切片法在光学显微镜下观察小孢子发育过程。【结果】农系928cms-Q1261雄穗无花药外露，花粉败育彻底，不育性表现稳定；质不育基因来自自交系Q1261，为S型；核不育基因来自农系928，由1对隐性基因控制；小孢子从单核晚期开始自溶，成熟期完全降解；自交系郑58能保持其不育性。【结论】农系928cms-Q1261属于S型不育胞质，是一种无花粉型的细胞质雄性不育系，其恢复系广泛。

Identification and Genetic Analysis of a Cytoplasmic Male Sterile Line in Maize(Zea mays L.)

【Objective】A new cytoplasmic male sterile line(Nongxi 928cms-Q1261) was identified for type of male sterile,stage of microspore abortion and genetic mechanism for its application to maize breeding.【Method】The male sterile expression was observed by planting sterile line in different locations and years.Testcross,sister cross and reciprocal cross were conducted with Nongxi 928cms-Q1261 to analyze the genetic characteristics of its male sterility.Meanwhile,the cytoplasmic type was discriminated by PCR amplification with specifically primers and the microspore genesis was observed under optical microscope by paraffin section technique.【Result】Results showed that the male sterility characteristics of Nongxi 928cms-Q1261 were stable,no anthers exposed on tassel and pollen aborted completely.The cytoplasmic male sterile gene,which was classified into S type of CMS,originated from Q1261,and its nuclear sterile gene originated from Nongxi 928,which was controlled by a pair of recessive genes.The microspores started degrading at the late stage of microspore and degenerated completely at the mature pollen stage.The male sterility of Nongxi 928cms-Q1261 could be maintained by inbred line Zheng58.【Conclusion】Nongxi 928cms-Q1261 belongs to S-type of CMS and is a non-pollen-type cytoplasmic male sterile line with many restorer lines.