控制普通野生稻种子休眠性QTL的定位

Mapping of QTLs for Seed Dormancy in Oryza rufipogon Griff.

水稻种子休眠性是关系到稻米品质和稻种质量的一个重要农艺性状。研究水稻种子休眠性遗传及分子机制对培育具有适度休眠性的优良水稻品种具有重要意义。本研究以籼稻品种9311为受体、普通野生稻为供体的染色体片段置换系群体为材料,在后熟不同时间检测群体种子休眠性,对控制种子休眠性的QTL进行定位分析,共定位到14个QTL,分布在第3、第4、第5、第6、第7、第10、第11、第12染色体上。筛选休眠性显著强于背景亲本9311的家系,分析这些家系携带的QTL数目,表明携带的位点越多,休眠性越强。进一步利用家系Q14与9311的F2群体验证了第7染色体标记RM180和RM21323之间存在一个效应较大的QTL q SD-7-2,该位点LOD值为18.49,可解释的表型变异率为33.53%,表明该位点是一个控制普通野生稻种子休眠性的主效QTL,且能稳定遗传。本研究为野生稻种子休眠基因的精细定位及克隆奠定了基础,且为培育强休眠性籼稻品种提供了育种材料。

Seed dormancy of rice is an important agronomic trait related to rice quality and quantity.Studies on genetics and molecular mechanisms of rice seed dormancy are of great significance in breeding fine rice varieties with moderate dormancy.In this research,a set of chromosome segment substitution lines(CSSLs),derived from an indica rice variety9311as the recurrent parent and the Oryza rufipogon Griff.as the donor parent,were used to detect the QTLs for dormancy of seeds at different storage dates after harvest.A total of14QTLs were detected on chromosomes3,4,5,6,7,10,11,and12.The lines with significantly stronger dormancy than the background parent9311were selected,showing the more dormancy loci in the lines the more strong dormancy.The F2population of the cross between Q14and9311was used to verify the QTLs for seed dormancy.A significant dormancy locus qSD-7-2was mapped on chromosome7between the markers RM180and RM21323,its LOD was18.49and the phenotypic variation rate was33.53%.On this major stable inherited QTL,the allele gene from Oryza rufipogon Griff.significantly increased the dormancy of seeds.These results are available for map-based cloning of major QTLs for seed dormancy,and provide the breeding materials for cultivating appropriate dormant rice varieties.