水稻雄性不育突变体012S-3的遗传分析和基因定位

Genetic Analysis and Gene Mapping of a Male Sterile Mutant 012S-3 in Rice

雄性不育是水稻杂种优势利用的重要资源,对雄性不育现象的研究具有重要理论意义和实践价值。本研究以自然突变的水稻雄性不育突变体012S-3为试验材料,对其表型特征和花粉育性等进行调查,并构建遗传群体,利用分子标记对目的基因进行初步定位,然后应用基因组重测序技术对其进行精细定位。结果表明,012S-3是一个典型的无花粉普通型雄性不育材料,其不育性状受1对隐性核基因控制。初步定位分析目的基因与SSR标记RM6081存在连锁关系,其遗传距离约为34.4 c M;进一步的精细定位分析,找到3个候选基因:LOC_Os07g35880、LOC_Os07g35920和LOC_Os07g35940,其中LOC_Os07g35880和LOC_Os07g35940编码β-淀粉酶,属于水稻中新发现的花粉致死基因。该不育基因的成功定位为其进一步的分离克隆及其在水稻分子设计育种中的应用奠定了基础。

Male sterility is an important resource for utilization of Heterosis in rice. Research on male sterility has important theoretical significance and practical value. In this study, we investigated the phenotypic characteristics and pollen fertility of the rice natural male-sterile mutant 012S-3. The genetic populations were constructed for preliminary positioning of the target gene, and genome sequencing technology were used for fine positioning of the, target gene. The results showed that 012S-3 was a typical non-pollen type mutant of male sterility and its sterility was controlled by a pairs of recessive nuclear genes. Preliminary mapping analysis indicated the objective gene and SSR marker RM6081 linkage, and their genetic distance was about 34.4 c M. By further fine mapping analysis, three candidate genes were found: LOC_Os07g35880, LOC_Os07g35920 and LOC_Os07g35940. In which, LOC_Os07g35880 and LOC_Os07g35940 encoding two putative β-amylases, belong to the new pollen lethal genes in rice. The successful positioning of the sterile gene laid a foundation for its further isolation, cloning and its application in rice molecular design breeding.