Study On Floral Bud Differentiation In Iris Germanica Cv. Lovely Again

The rules of floral bud differentiation in Iris germanica in the natural conditions in Beijing learned in this paper and some useful datum providing for flower period control,author choose the Iris germanica cv.Lovely Again as material,through the morphological observation and mensuration for four kinds of endogenous hormones and two main metabolites,the primary mechanism of flower bud differentiation studied in this paper.The process of floral bud differentiation in Iris germanica cv.Lovely Again was observed under the scanning electron microscope(SEM).The results were as follows:The process of flower bud differentiation can be divided into six stages from the beginning of flower bud differentiation,i.e.,inflorescence initiation, outer perianth initiation,stamen initiation,inner perianth initiation,pistil initiation,and beard hairs initiation. The whole process of floral bud differentiation finished in about fifty days.Petal-like pistils happened in the middle stage of carpel initiation.Maturing of beard hairs was an important symbol for flower open.Compared with the process of flower bud differentiation,four endogenous hormones mensurated with Enzyme-linked immunosorbent assay method(ELISA) during floral bud differentiation period,the samples were taken from the three different parts of plant body during the second floral bud differentiation period, apical bud,rhizome and leaf respectively.The results as follows:Both the indole-3-acedic acid(IAA) content and the gibberellic acid(GA₃) content decreased but both the zeatin riboside(ZR) and the abscisic acid(ABA) content increased in leaf during the early stage of flower bud differentiation and then changed in different ways in each other,changes of hormones in apical bud hardly more than in leaf and the changes' trend also different with in the leaf and rhizome.Measurement of total soluble sugars content by Anthrone Reagent,amounts of protein was mensurated by Commassie Blue G-250,the samples were taken from the three different parts of plant body during the second floral bud differentiation period,apical bud,rhizome and leaf respectively.The results as follows:(i ) Total soluble sugars content was highest in the early flower bud differentiation stage,and the relationship of soluble sugars content between the three different parts was:highest in rhizome,followed by the leaf and apical bud;(ii) The amounts of soluble proteins increased during the early initiation stage and then decreased, the climax of protein content occurred at the early stage of inflorescence initiation.We also found a balance relationship between the soluble sugars and proteins.Through the analysis for the process of morphological changing and the changes of two main metabolites during the floral bud differentiation period,maybe we can fertilization in the middle ten days in May to promote the bloom probability of the second flower bud differentiation in Iris germanica cv.Lovely Again, through the analysis for the rules of endogenous hormones during floral bud differentiation,we can get the conclusion that some apt exogenous hormones could be insufflated to control the flower period in Iris germanica cv.Lovely Again in last ten days in May.