银杏实生树不同发育阶段个体内源激素含量的变化

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。

Study on the Changes of Content of Endogenous Hormones at Different Developmental Stages of Ginkgo biloba Seedling

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.