水稻ptc1隐性核不育系的创制及其配合力分析

Creation and combining ability analysis of recessive genic sterile lines with a new ptc1 locus in rice

细胞质雄性不育系和光温敏雄性不育系是目前杂交水稻育种、制种中广泛利用的两种不育系,然而这两种不育系分别具有组配不自由和育性不稳定的缺陷。隐性核雄性不育系可以克服上述缺陷,创制、鉴定和利用细胞核雄性不育系将成为新一代杂交水稻技术的重要环节。本研究通过筛选9311的辐射诱变突变体库,获得了一个无花粉型隐性核雄性不育突变体ptc1-2。图位克隆发现ptc1-2的突变位点位于9号染色体上,是一段包含PTC1编码区在内259.37 kb的大片段缺失。共分离检测表明,雄性不育表型是由ptc1-2突变位点造成的。通过分子标记辅助选择将ptc1-2突变位点回交转育至两系不育系C815S和三系保持系五丰B中,在BC3F3世代分别获得与轮回亲本性状相似的隐性核不育系C815G和五丰G。配合力分析表明,C815G和五丰G分别具有与C815S和三系不育系五丰A基本相同的配合力水平。本研究为隐性核不育系的创制提供了新的基因和材料资源,并证实了隐性核不育系代替现有三系和两系不育系的可行性。

Cytoplasmic male sterile(CMS)lines and photoperiod/thermo-sensitive genic male sterile(PTGMS)lines are widely used as female parents in the commercial production of rice hybrid seeds.however,both systems have their intrinsic defects such as low usage of germplasm resources and unstable sterility.Recessive genic male sterile(GMS)lines,which overcome the pro-blems of CMS and PTGMS lines,have played a key role in the development of next generation technologies for rice hybrid seed production.In this study,a GMS mutant ptc1-2 without pollen grains was identified from an irradiation-induced mutant library of 9311.Using a map-based cloning approach,a 257.37 kb deletion region was detected,which contained entire coding region of PTC1 on chromosome 9.PCR co-segregation analysis showed that the male sterility was completely associated with the ptc1-2 deletion region.The ptc1-2 deletion locus was then introgressed into a PTGMS line C815S and a CMS maintainer line Wufeng B by marker-assisted backcrossing.Corresponding GMS lines C815G and Wufeng G were obtained at BC3F3 generation,which showed the phenotypical similarity to the C815S and Wufeng B lines,respectively.Combining ability tests revealed that C815G and Wufeng G had the same combining ability as C815S and the CMS line Wufeng A in conventional field,respectively.These results indicated that ptc1-2 was a new allele of PTC1,which could be applied for breeding GMS lines and be the potential of GMS lines in rice hybrid seed production.