Morphological and Endogenous Hormones Characteristics of Flower Bud of Siraitia grosvenorii during Its Differentiation
Morphological changes were observed by the paraffin section method,and the content changes of endogenous hormones were determined by ELISA for male,female and bisexual flower buds of Siraitia grosvenorii.The results showed that:First,the whole process of their flower bud differentiation could be divided into seven phases,including flower bud undifferentiation phase,flower bud initial differentiation phase,inflorescence differentiation phase,sepal primordial differentiation phase,petal primordial differentiation phase,stamen primordial differentiation phase and pistil primordial differentiation phase.Morphological characters of three kinds of flower buds were same before the stamen primordial differentiation phase,that stem apical were conical in flower bud undifferentiation phase,stem apical changed into flat from hemispherical in flower bud initial differentiation phase,spikes were initiated at 5-7 bits away from the stem apical in inflorescence differentiation phase,five sepal primordial were initiated around the small flower primordial in sepal primordial differentiation phase.While in the phase of stamen and pistil primordial differentiation,there were significant differences in morphological characters of the three kinds of flowers bud differentiation.After the pistil appeared inside of the stamen primordial,stamen primordial continued to develop into stamens and female primordial stopped growth then reduced to a small projection in male flower buds.The pistil primordial continued to develop into pistils and the stamen primordial grew slowly then reduced to small filaments in female flower buds.But,both the stamen and pistil primordial continued to develop into the normal stamens and pistils in bisexual flower buds.Second,the variations of endogenous hormones ABA,GAs and ZR contents were similar in the course of the three flower bud differentiation.ABA content decreased in flower bud physiological differentiation period and increased in flower bud morphological differentiation period,while the contents of GAs and ZR were maintained.There were significant differences of the IAA content in the course of the three flower bud differentiation,increased in flower bud physiological differentiation period and decreased in flower bud morphological differentiation period of the female flower buds,while the content was maintained in male and bisexual flower buds.The endogenous hormone ratios of ABA/GAs,ABA/IAA,ZR/ IAA and ZR/GAs had the similar variation in the three kinds of flower bud differentiation.ABA/GAs decreased in flower bud physiological differentiation period and increased in flower bud morphological differentiation,while the ratios of BA/IAA,ZR/IAA and ZR/GAs were maintained.The studies suggested that the flower bud differentiation processed through hermaphrodite primordium phase,and high ABA content and the ratio of ABA/GAs were beneficial to flower bud differentiation in Siraitia grosvenorii.IAA possibIy made an important role during sex differentiation of Siraitia grosvenorii.
NETL
NSTL
万方数据
维普
