修剪措施对紫叶紫薇花蕾中内源激素和碳氮营养含量的影响

Effects of Pruning Measures on Endogenous Hormones,Carbon and Nitrogen Nutrition in Flower Buds of Purple-leaf Lagerstroemia indica

为探讨修剪措施对二次开花的紫叶紫薇花蕾中内源激素和碳氮营养含量的影响,为指导紫叶紫薇花期调控提供理论依据,该研究以‘丹红紫叶’为试验材料,在一次花的末花期对主花枝进行重度修剪,以不进行修剪为对照(CK),分析不同处理下紫叶紫薇花蕾中主要花发育时期的吲哚乙酸(IAA)、脱落酸(ABA)、赤霉素(GA_(3))、玉米素核苷(ZR)、可溶性糖、淀粉、全氮含量的变化。结果表明:(1)修剪处理后,紫叶紫薇花蕾中内源ZR含量在各花发育时期显著升高;内源GA_(3)含量在花芽分化期降低,在初花期至末花期显著升高;内源IAA含量在花芽分化期显著升高,在初花期至末花期降低;内源ABA含量变化不显著。(2)修剪处理后,紫叶紫薇花蕾可溶性糖含量较对照组先升高后降低,在末花期变化达到显著水平;其淀粉、全氮含量增加但未达到显著水平。(3)紫叶紫薇花蕾中碳氮比总体呈上升趋势,修剪处理后其碳氮比值小幅度提高。研究认为,修剪措施能够影响紫叶紫薇内源激素水平变化,并通过调控碳水化合物与全氮含量影响花蕾中碳氮营养代谢,从而促进了紫叶紫薇二次成花、花期延长。

To explore the effects of pruning measures on the endogenous hormone contents,carbon and nitrogen nutrition contents in Purple-leaf Lagerstroemia indica flower buds of secondary flowering,and provide a theoretical basis for florescence regulation,we took L.indica‘Ebony Embers’as experimental materials in this study.The severe pruning were carried out on main flowering branches in late flowering period with no pruning as control.The changes of indole acetic acid(IAA),abscisic acid(ABA),gibberellin(GA_(3)),zeatin riboside(ZR),soluble sugar,starch and total nitrogen contents in flower buds of Purple-leaf L.indica under different treatments were analyzed.The results showed that:(1)the content of endogenous ZR in flower buds of Purple-leaf L.indica increased significantly at each flower development stage after pruning.The content of endogenous GA_(3) decreased at the stage of flower bud differentiation,and increased significantly from the initial flowering stage to the late flowering stage after pruning.The endogenous IAA content increased significantly at the stage of flower bud differentiation,and decreased from the initial flowering stage to the late flowering stage after pruning.The endogenous ABA content did not change significantly after pruning.(2)The content of soluble sugar in flower buds of Purple-leaf L.indica increased at first and then decreased after pruning,and reached a significant level at the late flowering stage.The content of starch and total nitrogen increased,while the difference was not significant.(3)The C/N ratio in flower buds of Purple-leaf L.indica in general,and the C/N ratio increased slightly after pruning.The study argued that pruning affects the endogenous hormone levels of Purple-leaf L.indica,and effects the metabolism of carbon and nitrogen nutrition in flower buds by regulating the contents of carbohydrate and total nitrogen.Pruning promotes the secondary flowering and prolongs the blooming period of Purple-leaf L.indica.