银杏实生树不同发育阶段个体内源激素含量的变化

Study on the Changes of Content of Endogenous Hor mones at Different Develop mental Stages of Ginkgo Biloba Seedling

以不同年龄银杏实生树为试材,研究芽尖和叶片中内源激素赤霉素(GA3)、玉米素(ZT)、吲哚乙酸(IAA)和脱落酸(ABA)含量与个体发育阶段的关系。结果表明,7龄期和13龄期银杏实生树芽尖和叶片中上述4种内源激素含量无明显差别,同时与13龄期首次开花的雄株接近,但却和3龄期有显著差异。可见实生树在7龄期前后树高2.5～3.0m已处转变期;随后树体继续生长增高到12～13m,在13龄期前后首次出现雄花和雌花开始进入成年期。芽尖中上述4种内源激素水平不是转变期进入成年期的惟一控制因子。转变期长可能是实生树迟果的原因之一。

Ginkgo seedlings of different ontogenetic stages were used for studying the relationships among ontogenetic stages and the content of endogenous hormones,such as GA 3 ,ZT,IAA and ABA in leaf and bud tip.The results showed that the content of these endogenous hormones in the leaf and bud tip of7-year-old and13-year-old seedlings was similar,without great difference;and moreover it was nearly same as the content of the first flowering male trees.It is likely that the seedling enters the transitional phase at7-year-old when the tree height is about 2.5～3.0m,then when growing to12～13m,enters adult stage at13-year-old with the first staminate flowers and pistillate flowers.It is believed that the endogenous hormones in bud tip were not the only factors controlling the transition to adult stage.