内源吲哚乙酸、脱落酸和赤霉酸与棉铃发育及脱落的关系

气相色谱分析的结果表明,开花后5～6天,不受精即将脱落棉铃里IAA和ABA的含量显著高于对照;GA_3处理的铃中IAA和ABA的含量则明显低于对照。IAA和GA_3含量在开花后第10天达到高峰,以后迅速下降,至第30天。又出现第二峰胚珠和纤维里尤为明显。ABA含量在开花后第15天达得高峰,以后下降,到第30天,又逐渐上升。棉纤维伸长及干重增加的最快速率与这三种激素的含量高峰密切相关。

RELATIONSHIP BETWEEN THE CHANGES IN THE LEAVES OF ENDOGENOUS HORMONES AND THE DEVELOPMENT OF COTTON FRUITS

Dynamic changes of endogenous IAA, GA_3 and ABA levels in young cotton boll with relation to fruit development and abscission were studied with gasliquid chromatography. The contents of IAA and ABA in bolls (both lint with ovules and shell) increased remarkably on the 5th to 6th day since flowering. During that period, the unfertilized bolls (styles and anthers dha been removed at the very beginning of flowering) dropped and their IAA and ABA contents were found higher than those of the normal. Application of exogenous GA_3 resulted in lowering the levels of these two hormones.The levels of IAA and GA_3 reached a peak on the 10th day and then falled Sharply, but generally there was a second rise on the 30th day. AS for ABA, a peakappeared at the 15th day, since then the level remained rather high.The rate of lint growth including fiber elongation and dry weight increase agreed with the level changes of these hormones.