Positional cloning of flowering time QTLs conferring adaptability to wide cultivation area in Japanese rice cultivars.

各地水稻品种的开花时间因生长季节的不同而不同。数量性状基因座(QTL)分析表明，两个QTL(Hd16和Hd17)控制着水稻品种Koshihikari和Nipponbaum的开花时间差异。基因组区域的高分辨率定位和序列分析使我们能够专注于每个QTL的候选基因。与对照相比，在短日照和长日照条件下，含有Hd16候选基因的转基因植株的开花时间都发生了变化。Hd16与hd2之间存在显著的双基因互作效应，hd2以前被认为是水稻开花时间的QTL。

Flowering time of rice cultivars has diversified to adjust to the growing season in each local cultivation area. Quantitative trait locus (QTL) analysis revealed that two QTLs (Hd16 and Hd17) were involved in the difference of flowering time between the rice japonica cultivars Koshihikari and Nipponbare. High-resolution mapping and sequence analysis of the genomic regions enabled us to focus on candidate genes for each QTL. Compared to control lines, flowering time in transgenic plants with a genomic fragment containing the Hd16 candidate gene was changed under short and long day-length conditions. Significant digenic interaction of Hd16 was observed with Hd2, which was previously identified as a flowering time QTL in rice.