利用水稻重组自交系群体定位分蘖数性状的QTL

Mapping QTLs for Tiller Number Traits Using Rice Recombinant Inbred Lines

分蘖数是水稻株型和产量形成的重要的性状。为了解析水稻分蘖数性状的遗传基础和鉴定分蘖数性状的新数量性状基因座位(quantitative trait locus,QTL),本研究利用少蘖粳稻品种‘魔王谷’和多蘖籼稻品种‘CO39’杂交后多代自交构建的重组自交系群体,对控制水稻分蘖数性状的QTL进行了基因定位。结果表明:3年共检测到4个控制分蘖数的QTL。第5染色体定位2个QTL qTN5.1和qTN5.2,分别位于标记RM3870~RM6972和RM3381~RM1237间,可解释的表型变异为7.88%和12.96%。第12号染色体2个QTL qTN12.1和qTN12.2,位于标记RM5746~RM2935和RM5746~SFP124间,可解释11.08%和10.26%的表型变化。QTL共定位表明qTN12.1/12.2为新的控制分蘖数的QTL,而qTN5.1和qTN5.2分别与13和8个已知QTL共定位或紧邻。这些结果为进一步精细定位和克隆水稻分蘖数QTL和分子辅助选择育种利用提供了一定的理论依据。

Tiller number is an important agronomic trai t for plant architecture and yield formation in rice.To elucidate the genetic basis and identify novel QTLs in controlling rice tiller number,a group of recombinant inbred lines(RILs)from the cross between japonica rice variety’Mowanggu’and indica rice cultivar’CO39’was used for detecting the quantitative trait locus(QTL)responsible for tiller number.The results showed that a total of 4 QTLs were mapped on chromosome 5 and 12.Two QTLs qTN5.1 and qTN5.2 on chromosome 5 located respectively in the interval of SSR markers RM3870~RM6972 and RM3381~RM1237,with the phenotypic variations of 7.88%and 12.96%.The QTLs qTN12.1 and qTN12.2 on chromosome 12 were mapped in the interval of RM5746~RM2935 and RM5746~SFP124,and explained the phenotypic contribution of 11.08%and 10.26%.Furthermore,the qTN12.1/qTN12.2 was confirmed to be a novel QTL controlling rice tiller number trait without co-localized known QTLs,while qTN5.1 and qTN5.2 were co-localized with 13 and 8 mapped QTLs.These results paved a foundation for further fine mapping and cloning the target QTL genes and for rice breeding with marker-assisted selection.