水稻苗期形态性状的QTL定位

Mapping QTLs for morphological traits at rice (Oryza sativa L.) seedling stage

采用苗期形态性状上有着明显差异的粳稻Asominori和籼稻IR24杂交产生的重组自交系(RILs)为材料,经营养液培养后,对水稻苗期形态相关的6个数量性状:最大根长(MRL)、苗高(SH)、根干重(RDW)、茎(叶)干重(SDW)、总重(TW)以及根/茎(叶)干重比(RSR)进行了数量性状位点(QTL)定位分析.结果共检测到影响6个形态性状的8个QTL位点,分别位于水稻的第2,4,10和11染色体上,其贡献率为9.79%～22.90%.并发现位于第4染色体上的控制根/茎(叶)干重比的qRSR-4和根干重的qRDW-4的2个位点以及位于第10染色体上的控制茎(叶)干重的qSDW-10和总重的qTW-10的2个位点分别位于同一分子标记区间.研究结果对水稻苗期形态性状QTL的精细定位及培育理想株型具有一定的应用价值.

This study was conducted to identify quantitative trait loci（QTLs） associated with maximum root length（MRL）, shoot height （SH）, root dry weight（ RDW）, shoot dry weights （SDW）, total weight（TW） and root/shoot ratio of dry weight（RSR）, mainly representing the seedling morphological characteristics using a recombinant inbred lines （RILs） derived from a cross between a japonica variety, Asominori and an indica variety, IR24, cultivated by hydroponics. Resultantty, eight QTLs for six seedling morphological traits were detected on chromosome 2 （three QTLs）, 4（two QTLs）, 10（two QTLs）, 11, respectively, which could explain 9.79% - 22.90% of total phenotypic variance. Interestingly, it was found that the genomic region of qRSR- 4 for RSR coincided with qRDW -4 for RDW on chromosome 4, and the region of qSDW - 10 for SDW did with qTW - 10 for TW on chromosome 10, respectively. The results will be useful in fine mapping for genes associated with seedling - morphology and breed- ing ideal seedling morphology in rice.