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水稻核隐性雄性不育系的创制及其在多系品种培育中的应用

Development of Rice Recessive Genic Male Sterile Lines and Their Application in Multi-line Varieties Breeding

  • 摘要: 目前,水稻育种目标已从过去片面追求产量,转向优质、高产、多抗等多性状综合平衡发展。综合利用已鉴定的水稻优良农艺性状功能基因成为水稻育种发展的必然趋势。在聚合利用多个控制水稻有利性状的基因时,传统培育纯系亲本的技术思路存在明显的局限性,而培育多系品种能够规避这些局限,被视为突破当前水稻育种瓶颈的重要技术途径。将核隐性雄性不育系应用于多系品种品系的回交选育,可大幅提高育种效率,并有助于打破连锁累赘。利用CRISPR-Cas9技术在粳稻中对TDR基因进行定点敲除,通过潮霉素抗性标记筛选获得阳性转基因植株,经PCR鉴定与测序分析,筛选得到了无转基因成分的不育株系;同时建立了纯合不育株系的繁殖方法,构建基于该核隐性雄性不育系培育多系品种的技术方案。通过CRISPR-Cas9技术定点敲除TDR基因创制水稻不育新材料,配套建立的不育株系繁种方法及多系品种培育技术方案,对水稻多系品种选育与应用具有重要的参考价值。

     

    Abstract: At present, the goal of rice breeding has shifted from one-sided emphasis on yield in the past to comprehensive and balanced development of many traits such as high quality, high yield and multi-resistance. It is an inevitable trend for future breeding to comprehensively utilize the identified favorable genes that control excellent agronomic traits. There are obvious limitations in the traditional technical thinking of cultivating pure-line parents when pyramiding multiple genes controlling favorable traits in rice. In contrast, the development of multi-line varieties can avoid these limitations and is regarded as an important technical strategy to break through the bottleneck of current rice breeding. The application of recessive genic male sterile lines in the backcross breeding of multi-line varieties can greatly improve breeding efficiency and help to break the linkage drag. In this study, the TDR gene was site-specific knocked out in japonica rice using the CRISPR-Cas9 system. Positive transgenic plants were obtained by hygromycin resistance marker screening, and sterile lines free of transgenic components were acquired via sequencing and PCR analysis. A method for the propagation of homozygous male sterile lines, as well as a technical scheme for breeding multi-line varieties using this recessive genic male sterile line were obtained. The generation of novel rice sterile materials by site-specific knockout of the TDR gene using CRISPR-Cas9 technology, together with the matched propagation method for sterile lines and technical scheme established for multi-line variety cultivation, possesses important reference value for the breeding and application of rice multi-line varieties.