几种调控措施对龙眼顶芽激素及成花坐果的影响

Effects of several regulation measures on change of endogenous hormones in terminal bud at flowering stage and the flower-formation and fruit-setting of Longan

关键词:  调控措施  花期  顶芽  内源激素  成花坐果

Key words:  regulation measures  flowering stage  terminal bud  endogenous hormones  flower-formation and fruit-setting

摘要:

以当地主栽龙眼品种‘泸丰一号'为材料,在龙眼花芽形态分化期开始前,采取树冠喷施不同比例的生理调节剂、骨干枝环割、断根等调控措施,定期测定花芽分化期顶芽内源激素,在花芽分化完成后统计成花坐果率,研究调控措施对龙眼顶芽激素含量动态变化和成花坐果率的影响。结果表明:几种措施处理都不同程度地提高了龙眼的成花坐果率,适当浓度(150 mg·L^-1及100 mg·L^-1)乙烯调节剂组合调控措施可以显著提高树体的雌花数、雌花率及坐果率,其中雌花率分别比对照提高了32.57%和38.22%; 各处理的冲梢率显著低于对照,其中处理B(100 mg·L^-1乙烯利调节剂组合)的冲梢率(18.58%)最低,比对照低34.18%,且芽轴增长率与冲梢率呈显著正相关,其中以150.00 mg·L^-1多效唑+100.00 mg·L^-1乙烯利+1.0 mg·L^-1细胞分裂素配制好的药液均匀喷洒在树冠上的处理效果最优。几种措施对于龙眼顶芽中的激素及激素的平衡的影响表现为GA₃含量和ABA含量在花序主轴分化期较高,在多级侧花序快速分化期则处于较低水平,整个形态分化期ZT始终保持较低水平,则利于防止龙眼成花逆转,从而促进龙眼花芽分化; IAA含量受各处理影响变化较为复杂,并未呈现出较强的规律性; 从激素比例方面看,龙眼顶芽在花序主轴分化前期IAA/GA₃比值较低,末期ZT/GA₃比值较高则有利于成花,在整个形态分化期ZT/ABA及GA₃/ABA都处在较低的水平,可有效抑制成花逆转。研究结果可为龙眼的成花机理以及四川泸州地区龙眼的优质丰产栽培提供理论依据。

Abstract:

In this paper,‘Lu Feng No.1' which is mainly cultured longan varieties in Luzhou was chosed as the research object. And we chose some experimental measurements on the basis of the local methods to promote floral bud differentiation. Before flower bud morphological differentiation,taking several regulation measures of spraying growth regulator in different proportions,girdling the primary branches and root pruning with coating the earth,we regularly measured endogenous hormones in terminal bud at flower bud differentiation period by every 15 d. When the differentiation finished,we calculated the rate of flower and fruit setting to discuss effects of regulation measures on change of endogenous hormones in terminal bud at flowering stage and flower formation and fruit setting. We analysed all experimental data for researching mechanism of flower formation. The result showed that all of these measures improved flower rate and fruit setting rate in different degrees remarkably. However, the control measures of ethylene regulator combination with appropriate concentrations(150 mg·L^-1 and 100 mg·L^-1)could improve the number of trees female flowers, female flowers rate and fruit-bearing rate of trees, among which the female flowers rate improved respectively by 32.57% and 38.22% than CK, the tip-blunting rate of each treatment was significantly lower than CK,and the tip-blunting rate(18.58%)of treatment B(100 mg·L^-1 ethylene regulator combination)was the minimum,which was 34.18% lower than CK,and the growth rate of bud axis and tip-blunting rate have significant positive correlation. The different treatments improved the flowering and fruit-bearing status of longan body in different degrees,inhibited flowering reversion occurring effectively, and the effects of the treatment spraying mixed liquor consisted of 150.00 mg·L^-1 mutli-effect triazole an 100.00 mg·L^-1 ethephon and 1.0 mg·L^-1 6-benzylaminopurine evenly in the crown most excellent. For the hormones in terminal buds,these contents and hormone balance were changed by the different measures. The results were as follows: with higher GA₃ and ABA contents in the spindle differentiation stage,then GA₃ content and ABA content keeping at a low level in multilevel side inflorescence rapidly-differentiation stage,lower ZT level in the entire morphological differentiation,and that was good for preventing longan flower from reversing and promoting longan bud differentiating. The change of IAA content affection was relatively complex,and its regularity was not strong. Viewing the point of hormones content proportion,smaller ratio of IAA/GA₃ in the spindle differentiation stage,the bigger ratio of ZT/ABA before purple inflorescence primordia appearing-period and the lower ratio of ZT/ABA and GA₃/ABA in hole morphological differentiation,which were beneficial to longan flowering. The study would provide theoretical basis for Luzhou longan high quality and high yield cultivation.