光周期对菊花花芽分化和内源激素的影响

本试验以菊花品种"秀芳白"为试材,研究了不同光周期(昼/夜分别为16h/8h,12h/12h和8h/16h)对菊花花芽分化及其过程中内源激素IAA、GA3、CTK和ABA含量的影响。结果表明,16h/8h处理的植株始终没有花芽分化;8h/16h处理的植株从处理到花芽分化开始和花芽分化完成所需天数分别为12.8 d和25.1 d,比12h/12h处理的分别提前2.4 d和4.7 d。花芽分化过程中16h/8h处理的IAA和GA3含量呈现缓慢下降趋势,而8h/16h处理和12h/12h处理的呈现迅速下降趋势;16h/8h处理的CTK和ABA含量没有出现明显变化,而8h/16h处理和12h/12h处理的呈现上升趋势。CTK/IAA、CTK/GA3、ABA/IAA以及ABA/GA3在16h/8h处理区没有明显变化,而在8h/16h处理和12h/12h处理区呈现上升趋势。说明短日照促进菊花花芽分化,而且日照时数越短,花芽分化越快;花芽分化过程中叶片GA3和IAA含量减少,CTK和ABA含量增加,而且CTK/IAA和CTK/GA3以及ABA/IAA和ABA/GA3比值增加,有利于菊花花芽分化和提早开花。

Effects of Photoperiod on Floral Bud Differentiation and Contents of Endogenous Hormones in Chrysanthemum

Effects of different photoperiods(day/night: 16h/8h,12h/12h and 8h/16h) on floral bud differentiation and the contents of endogenous IAA,GA3,CTK and ABA hormones of chrysanthemum leaves during these treatments were studied with cut flower chrysanthemum cultivar Dendranthema grandiflora "Xiufangbai".The results showed that floral bud was not found in 16h/8h treated plants throughout the experiment.The time from beginning of treatment to that of floral bud differentiation and from beginning to ending of differentiation of 8h/16h treatments were 12.8 days and 25.1 days respectively,which advanced by 2.4 days and 4.7 days than those of 12h/12h treatments.Contents of IAA and GA3 decreased slowly in 16h/8h treated plants but quickly in 12h/12h and 8h/16h treated plants during floral bud differentiation.Contents of CTK and ABA did not change significantly in 16h/8h treated plants,while they increased significantly in 12h/12h and 8h/16h treated plants.The ratio of CTK/IAA,CTK/GA3,ABA/IAA and ABA/GA3 did not change obviously in 16h/8h treated plants,while they increased in 12h/12h and 8h/16h treated plants.The results indicated that short-day treatment enhanced floral bud differentiated.The shorter the day time was,the faster the floral bud differentiated.During floral bud differentiation of chrysanthemum,contents of IAA and GA3 decreased,while contents of CTK and ABA and the ratios of CTK/IAA,CTK/GA3,ABA/IAA and ABA/GA3 increased,which enhanced the floral bud differentiation and flowering.