Abstract: The relationship between the leaf angle of different rice varieties and fertilizer treatments and the levels of endogenous zeatin and gibberellin were studied. The results showed that,when the level of endogenous zeatin was lower and gibberellin higher,the leaf angle was larger,and vice versa. This was further proved by an additional experiment applying exogenous zeatin and gibberellin.The leaf angle was also significantly affected by spraying auxin,MET and TIBA.It was also observed that,when the rice plant had higher contents of structural and storage substances in leaves and sheaths,and well-developed mechanical structure in leaves and lamina joints, the leaf angle was decreased,and vice versa. On the basis of the similar effects of endogenous and exogenous hormones, it was concluded that phytohormones affected the leaf angle through changing the contents of structural substances and the mechanical structure.

Key words: Leaf angle, Endogenous hormones, Substances in leaves and sheaths, Structure in leaves and lamina joints

摘要： 不同品种和肥料处理的叶角与内源激素含量存在下列关系:玉米素含量低,赤霉素含量高时叶片披垂、叶角较大:而玉米素含量高、赤霉素含量低时叶片挺立、叶角较小。施用外源玉米素、赤霉素对叶角的影响验证了这一结果;施用生长素及多效唑、三碘苯甲酸亦显著影响叶角。各处理叶成分、叶结构与叶角的关系表现为:当叶结构物质和贮藏物质含量高、叶机械组织发达时叶角较小;反之叶角较大。根据内、外源激素作用的一致性可以认为:激素通过叶结构物质、叶机械组织的变化而影响叶角。

关键词: 叶角, 内源激素, 叶成分, 叶结构