Chinese Journal OF Rice Science ›› 2022, Vol. 36 ›› Issue (3): 259-268.DOI: 10.16819/j.1001-7216.2022

• Research Papers • Previous Articles     Next Articles

Screening and QTL Mapping of Heat-tolerant Rice (Oryza sativa L.) Germplasm Resources at Seedling Stage

LIU Jin1,2, CUI Di2, YU Liqin1, ZHANG Lina2, ZHOU Huiying1, MA Xiaoding2, HU Jiaxiao1, HAN Bing2, HAN Longzhi2,*(), LI Maomao1,*()   

  1. 1Rice Research Institute, Jiangxi Academy of Agricultural Sciences/National Engineering Research Center for Rice(Nanchang), Research Center of Jiangxi Crop Germplasm Resources, Nanchang 330200, China
    2National Key Facility for Crop Gene Resources and Genetic Improvement / Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
  • Received:2021-07-29 Revised:2021-08-19 Online:2022-05-10 Published:2022-05-11
  • Contact: HAN Longzhi, LI Maomao

水稻苗期耐热种质资源筛选及QTL定位

刘进1,2, 崔迪2, 余丽琴1, 张立娜2, 周慧颖1, 马小定2, 胡佳晓1, 韩冰2, 韩龙植2,*(), 黎毛毛1,*()   

  1. 1江西省农业科学院 水稻研究所/水稻国家工程研究中心(南昌)/江西省农作物种质资源研究中心,南昌 330200
    2中国农业科学院作物科学研究所/农作物基因资源与基因改良国家重大科学工程, 北京 100081
  • 通讯作者: 韩龙植,黎毛毛
  • 基金资助:
    国家重点研发计划资助项目(2016YFD0100101);国家重点研发计划资助项目(2016YFD0100101-11);江西现代农业科研协同创新专项(JXXTCX202101);国家农作物种质资源保护项目(2019NWB036-01);国家农作物种质资源保护项目(2019NWB036-12-2);国家农作物种质资源平台资助项目(NCGRC2020-02);国家农作物种质资源平台资助项目(NCGR2021-055)

Abstract:

【Objective】Identification of germplasm resources and genes extremely resistant to heat will provide technical support and lay a physical foundation for the breeding of new heat-tolerant rice varieties. 【Method】Heat tolerance level and survival rate are used to identify the high temperature resistance of rice at seedling stage, so as to select heat-tolerant germplasm resources and identify major QTLs. 【Results】There are obvious differences in heat tolerance among different varieties at seedling stage. Indica rice has significantly stronger tolerance to heat than japonica rice. Twenty accessions of rice germplasm resources with strong heat tolerance, such as Jiayu 253, Zhongyouzao 8, and Xiushui 09, were selected. The survival rates, growth and development of these varieties were almost immune to high temperature. Furthermore, there are significant differences in heat tolerance between the parents. Zhongyouzao 8 has strong heat resistance, while Longdao 5 is sensitive to high temperature. The phenotype followed an approximate continuous normal distribution under high temperature in the RIL populations. Twelve QTLs were detected on chromosomes 1, 3, 4, 5 and 8, and these QTLs have a significant genetic overlap for heat resistance grade(HTG) and survival rate under heat stress(HTSR). The major QTL clusters qHTS4 and qHTS8 have significant heat tolerance function. Based on the preliminary QTL mapping results, the RHL-F2 population was used to validate the stably expressed major QTL qHTS8, which was identified on the chromosome 8 between RM5808 and RM556 regions. 【Conclusion】 Twenty accessions of rice germplasm resources with strong heat tolerance were selected, twelve QTLs were identified, and then the major QTL qHTS8 was verified to have strong effects on regulating heat tolerance. These results will lay a foundation and provide abundant germplasm resources for the research on the physiological, biochemical, and molecular genetic mechanism of heat resistance and rice breeding.

Key words: rice, seedling stage, heat tolerance, germplasm screening, QTL

摘要:

【目的】鉴定和筛选水稻极端耐热种质或基因,为培育耐高温水稻新品种提供技术支撑。【方法】以耐热等级和幼苗存活率为指标对不同类型水稻苗期耐热性进行鉴定评价,以筛选和鉴定耐热种质资源及主效QTL。【结果】不同类型水稻品种苗期耐热性存在明显差异,籼稻品种耐热性明显强于粳稻品种,籼稻和粳稻品种均存在极端耐热和极端敏感种质资源;共筛选出嘉育253、中优早8号、秀水09等20份耐热种质资源,高温处理后幼苗存活率和生长发育基本不受影响。RIL群体双亲耐热等级和幼苗存活率存在极显著差异,中优早8号耐热性较强,植株基本无枯死,龙稻5号对高温胁迫较敏感,不同株系间苗期耐热性存在较大幅度变异;共检测到12个苗期耐热相关QTL,分布于第1、3、4、5和8染色体上,耐热等级和存活率QTL存在明显的遗传重叠,主效QTL簇qHTS4qHTS8表型贡献率较大。基于QTL初步定位结果,利用相对剩余杂合体RHL-F2群体,在第8染色体RM5808-RM556标记区域鉴定了一个苗期耐热性主效QTL qHTS8,该区域对苗期耐热性具有较强调控效应。【结论】筛选出20份苗期耐热性较强的水稻种质资源,鉴定了12个苗期耐热相关的QTL,定位和验证了一个调控水稻苗期耐热性的主效QTL qHTS8,研究结果可为水稻苗期耐热性生理生化机理与分子遗传机制的研究及育种利用奠定基础。

关键词: 水稻, 苗期, 耐热性, 资源筛选, 数量性状基因座