Abstract: According to the results of the experiments conducted in 2003-2005,Yongyou 6,a late season inter-subspecific hybrid rice combination derived from a japonica cytoplasmic male sterile line Yongjing 2A and an indica restorer line K264806,performed high yielding potential,which was closely related to its outstanding heterosis in plant morphology over the japonica inbred rice Xiushui 63 and indica hybrid rice Shanyou 63.At the early growth stage,the tiller number of Yongyou 6 was between that of Shanyou 63 and that of Xiushui 63,and it showed a moderate tillering ability and less non-effective tillers.At the middle growth stage,the culms,sheaths and leaves of Yongyou 6 grew faster with higher biomass.The population of Yongyou 6 had better light distribution in its canopy because of its three top upright,longer and cured leaves.At the late growth stage,although Yongyou 6 was of high plant,but it perfected very strong tolerance to lodging due to its long and closed sheathes and short and thick basal internodes.At the maturity stage,Yongyou 6 showed arc-shaped panicles with more primary and secondary branches.The grain density of panicle was moderate with more oblate grains.The root-shoot ratio of Yongyou 6 was very higher at the whole growth stage.Moreover,the ideo-plant morphology of indica-japonica inter-subspecific super high-yielding hybrid was also discussed.

Key words: inter-subspecific hybrid rice, super high-yielding, plant morphology, heterosis

摘要： 2003-2005年的试验结果表明，与常规晚粳稻秀水63和籼型杂交晚稻汕优63相比，三系籼粳亚种间杂交晚粳稻甬优6号的超高产与其生育期间株形特征及竞争优势密切相关。生育前期，甬优6号的分蘖数介于籼、粳稻之间，消长平稳，分蘖力中等，无效分蘖少；生育中期，植株的茎、鞘、叶生长快，生物量大，上3叶长而内卷挺立，群体上下受光态势好；生育后期，植株高大，茎秆粗壮，鞘叶长而抱秆紧密，茎基部节间短而厚重；成熟期，穗呈弧形，一、二次枝梗数特别多，粒多穗重，着粒密度适中，粒形偏团；各生育阶段的根冠比高。另外，对籼粳亚种间超级杂交稻的理想株形进行了讨论。

关键词: 亚种间杂交稻, 超高产, 株形, 竞争优势