秋季剪梢对温室蓝莓芽分化及内源激素的影响

Effects of Shoot Pruning in Autumn on Buds Differentiation and Endogenous Hormones of Vaccinium Spp.in Greenhouse

花芽分化是蓝莓开花结实的基础,秋季剪梢是温室蓝莓栽培管理中的重要措施之一,可有效调节其花芽分化。为探明秋季剪梢对温室蓝莓花芽分化及期间芽中内源激素变化的影响,于秋季对日光温室内5年生北高丛‘M7’蓝莓树体上的健旺直立枝条进行剪梢处理,以未剪梢为对照。在明确2种处理下新梢腋芽花芽分化差异的基础上,分析未剪新梢上、中部腋芽与剪梢后的新梢上部腋芽中赤霉素(gibberellin A_(3),GA_(3))、生长素(indoleacetic acid,IAA)、脱落酸(abscisic acid,ABA)和玉米素(zeatin,ZT)含量以及IAA/ABA、ABA/ZT的比值变化。结果表明,与未剪梢相比,剪梢处理明显加快了温室蓝莓花芽分化的进程,花芽数量和花芽率分别显著提高4和7倍,花芽直径显著提高78.26%;剪梢处理上部芽中的GA_(3)含量在其成花诱导期较未剪梢显著降低32.74%,而后花器官原基形成时期又持续升高,且显著高于未剪新梢上、中部芽内GA_(3)含量;剪梢处理上部芽内的IAA含量在其成花诱导期显著高于未剪梢中部芽,却显著低于未剪梢上部芽,在其花器官原基形成期显著低于未剪梢中部腋芽。在剪梢后留存新梢的上部腋芽成花诱导过程中,ABA与IAA呈极显著正相关关系,且ABA/ZT值先大幅升高,且显著高于未剪梢中部芽;而在剪梢上部芽的花器官原基形成过程中,IAA/ABA的值均高于未剪枝中部芽。即秋季剪梢处理通过先大幅降低芽内GA_(3)和ZT的含量、升高IAA含量并提升ABA/ZT的比值来诱导温室蓝莓花芽分化并加快其花芽分化进程,而后通过提高GA_(3)含量、降低IAA含量,并维持较高的IAA/ABA值来促进温室蓝莓花器官原基的发育。以上结果为探讨秋季剪梢对蓝莓花芽分化的作用机理及温室蓝莓花芽分化的调控提供理论依据和技术支撑。

Flower bud differentiation is the basis of blueberry flowering and fruiting.Pruning shoots in autumn is one of important measures in greenhouse blueberry cultivation and management,which can effectively regulate flower bud differentiation,but its regulation mechanism is still unclear.To investigate the effect of shoot pruning in autumn on flower bud differentiation and endogenous hormone content in flower bud of blueberry in greenhouse,in autumn,the healthy and erect branches of 5-year-old‘M7’blueberry trees were pruned in a sunlight greenhouse,and the unpruned treatment was used as control.On the basis of confirming the difference of flower bud differentiation of axillary buds of new shoots under 2 treatments,the contents of gibberellin(GA_(3)),auxin(IAA),abscisic acid(ABA)and zeatin(ZT),and the ratio of IAA/ABA and ABA/ZT in the axillary buds of unpruned and pruned shoots were analyzed.The results showed that,compared with unpruned shoots(control),pruning significantly accelerated the process of flower bud differentiation of blueberry in greenhouse,and the number and percentage of flower buds were increased by 4 and 7 times,respectively,the diameter of flower bud increased by 78.26%.The content of GA_(3) in the upper buds of the pruned shoots decreased by 32.74%during the flowering induction period compared with that in the middle buds of the unpruned shoots,and then increased continuously during the floral organs primordium formation period,and significantly higher than the GA_(3) content in the upper and central bud in the unpruned shoots.The content of IAA in the upper buds of the pruned shoots was significantly higher than that in the middle buds of the unpruned shoots during flowering induction period,but significantly lower than that in the upper buds of the unpruned shoots,and significantly lower than that in the axillary buds of the middle buds of the unpruned shoots during the formation of the floral organs primordium.ABA was positively correlated with IAA during flowering induction of axillary buds in the upper buds of new shoots after pruning,and the ratio of ABA/ZT increased significantly at first and was significantly higher than that in the middle buds of unpruned shoots.The ratio of IAA/ABA was higher in the formation of floral primordium in the upper buds of pruned shoots than that in the middle buds of unpruned shoots.The shoot pruning in autumn could induce the flower bud differentiation and accelerate the flower bud differentiation of blueberry by decreasing the content of GA_(3) and ZT,increasing the content of IAA and maintaining high ratio of IAA/ABA.Above results provided a theoretical basis and technical support for exploring the mechanism of shoot pruning on the flower bud differentiation of blueberry.