【摘要】 为定位水稻发芽期和苗期耐冷性的QTL,鉴定新的耐冷基因位点,丰富水稻耐冷性的分子遗传基础。以籼型杂交稻恢复系品种泸恢99(Luhui 99,R99)和粳型超级稻品种沈农265(Shennong 265,SN265)杂交衍生的144个F8稳定遗传的重组自交系群体(Recombinant inbred lines,RILs)为试验材料,以低温条件下水稻种子发芽率和苗期叶片赤枯度为耐冷性鉴定标准,采用QTL Ici Mapping v3. 0软件基于完备复合区间作图法,对水稻发芽期和苗期耐冷性进行QTL分析。共检测到2个控制发芽期耐冷性的QTL和1个控制苗期耐冷性QTL,分别位于第3,5,9染色体上,命名为q LTG-3、q LTG-5、q SCT-9,3个QTL的LOD值分别为3. 60,2. 73,2. 52,加性效应为0. 09,-0. 10,-0. 09,可解释表型变异的11. 02%,14. 07%,12. 18%。其中,检测到控制发芽期耐冷性的q LTG-5位于分子标记R5M13～RS8,遗传距离约8.0 c M,该区间未见相关水稻耐冷性QTL的报道,可能是一个新的控制水稻发芽期耐冷性的QTL位点。更多还原

【Abstract】 The aim of the study was to locate the QTL of rice cold tolerance at germination and seedling stages,to identify new locus of cold tolerance gene,and to enrich the molecular genetic basis of rice cold tolerance.144 F8 stable recombinant inbred lines( RILs) derived from the cross between indica restorer line Luhui 99( R99)and super japonica cultivar Shennong 265( SN265) were used to identify the QTLs of cold tolerance at germination and seedling stages. The germination rate of rice seeds and the withered degree of leaves at seedling stage were used as the standards of cold tolerance,QTLs were mapped by QTL IciMapping v3. 0 software. Two QTLs controlling cold tolerance at germination stage and one QTL controlling cold tolerance at seedling stage were detected,which were located on chromosomes 3,5 and 9,respectively,named qLTG-3,qLTG-5 and qSCT-9. The LOD values of the three QTLs were 3. 60,2. 73,and 2. 52,and their additive effects were 0. 09,-0. 10,and-0. 09,respectively,which accounted for 11. 02%,14. 07%,and 12. 18% of phenotypic variation,respectively. Among them,qLTG-5 was located between R5 M13-RS8 markers with a genetic distance of 8. 0 cM on chromosomes 5,and no cold tolerance QTL was reported in this interval,so it might be a new QTL for cold tolerance at germination stage in rice. The results laid the foundation for fine mapping and cloning of related cold tolerance genes.更多还原