The differentiation process of flower bud and the changes of endogenous hormones in Syringa microphylla
Observing the process of flower bud differentiation,clarifying the correlation between morphology and anatomical structure of flower buds,and analyzing the dynamic changes of endogenous hormones can provide scien-tific basis for flowering regulation and cultivation management of Syringa microphylla.In this study,we examined flower bud differentiation and flowering characteristics of S.microphylla by external morphological observation and paraffin section technology,and measured the contents of endogenous hormones by enzyme-linked immunization(ELISA).According to the observation results of anatomical structure,flower bud differentiation of flowered S.mi-crophylla in spring began in late May and ended in early October.The flower bud differentiation process could be divided into seven stages:undifferentiated stage,spathe primordium differentiation stage,inflorescence primordium and small floral primordium differentiation stage,sepal primordium differentiation stage,petal primordium differen-tiation stage,stamen primordium differentiation stage,and pistil primordium differentiation stage.There were over-laps across different differentiation stages.Indole acetic acid(IAA),abscisic acid(ABA)and zeatin riboside(ZR)changed greatly and showed a variation pattern of"down-up-down","up-down-up-down"and"up-down",respectively.The content of gibberellin(GA3)remained stable at a low level with little variation throughout the whole process.The highest value of ABA/GA3 appeared in the differentiation stages of spathe primordium,sepal primordium,and petal primordium.The highest value of IAA/GA3 appeared in the undifferentiated stage,the inflo-rescence primordium and small floral primordium differentiation stage,and the petal primordium differentiation stage.The highest value of ABA/IAA appeared in the sepal primordium differentiation stage,while the highest val-ues of ZR/GA3 and ZR/IAA appeared in the differentiation stages of sepal primordium and petal primordium.The internal anatomical structure of flower bud differentiation was closely related to the external morphology.High levels of IAA,ABA,ABA/GA3 and IAA/GA3 were beneficial to the initiation of flower bud differentiation and the differ-entiation of early flower organ primordium,while the differentiation of sepal primordium and petal primordium required the accumulation of ZR,IAA,and ABA.The initiation stage of flower bud differentiation and the differen-tiation of sepal primordium and petal primordium may be the key periods of flower bud differentiation of S.micro-phylla,with an important role of the content of endogenous hormones and the balance between hormones.
万方数据
维普
