棉花花芽分化时期茎尖内源激素的变化

实验结果表明，从子叶展平后到肉眼可花芽（现蕾），所测几种激素（ABA、IAA、GA3、iPA、ZR）的含量均表现出明显的动态变化，而且在花芽分化临界期表现出最显著的变化（出现高峰或出现低峰）。推测所测几种激素均与花芽分化有密切关系。其中ABA、GA3和CTK（iPA、ZR）在花芽分化临界期时，其含量变化均呈现出一个高峰；而IAA则在花芽分化临界期时出现一个低峰。经比较分析得知，随着花芽分化的进行，ABA/IAA、GA3／IAA、CTK／IAA均表现一个较明显的变化规律。即从子叶展平时起，其比值开始上升，到花芽开始分化时达到一个峰值，之后逐渐下降，并维持在一个较稳定的水平。显然，ABA／IAA、GA3／IAA、CTK／IAA在棉花的花芽分化过程中起着重要的调控作用。由此推测，增加植物体内的ABA、GA3、CTK的含量或降低IAA的含量，都可以促进棉花的花芽分化；反之则抑制棉花的花芽分化。

Studies on endogenous hormone changes in the stem terminal of Gossypium hirsutum during flower bud differentiation

The results of experiment were that the contents of ABA?IAA?GA 3?iPA and ZR all appeared evident changes from cotyledon outspread to be in bud.Further more,those endogenous hormones appeared the most evident changes when flower buds began to differentiate.From the results of experiment,it was considered that flower bud differentiation was related to the above hormones.The contents of ABA?GA 3 and CTK (iPA,ZR) all appeared a peak and the content of IAA appeared evident decrease when flower buds began to differentiate.The changes of ratio of ABA to IAA,GA 3 to IAA and CTK to IAA were evident in the course of flower bud differentiation.In other words,the ratio began to rise till it peaked when flower buds began to differentiate,then it decreased and stayed a stable level.The results suggest that the ratio regulated the flower bud differentiation of cotton.It was concluded that increasing the contents of ABA?GA 3?CTK or decreasing the content of IAA could accelerate flower bud differentiation of cotton.