Morphological Observation And Studies On Dynamic Changes Of Endogenous Hormones At Pre-stage Of Flower Bud Differentiation Of Hemerocallis

To study on the Pre-flower bud Differentiation of Single-season flowering and Multi-season flowering of Hemerocallis fulva and Hemerocallis’Stella de Oro’under the natural climatic conditions in Beijing and also the variation of the Endogenous Hormones in the root,bud and leaf at the same time.In this paper,the author used the and Hemerocallis fulva and Hemerocallis’Stella de Oro’for the study materials, Through its flower bud differentiation in the process of morphological observation and the determination of endogenous hormones, we have a rudimentary understanding on the two different kinds of Hemerocallis fulva flower bud differentiation characteristics of the early morphological changes, as well as the variation of the endogenous hormone.(1) In this paper, the paraffin-cut section method was used for study on the Hemerocallis ’Stella de Oro’flower and Hemerocallis fulva bud to Observe the pre-flower bud differentiation process,the result showed that:Hemerocallis fulva bud differentiation started in early August and Into dormancy in Mid-November, In the meantime, it has gone through three differentiation period:undif-ferentiation (Early August early to mid September),inflorescence initiation (Last ten days to September mid October),outerperianth initiation (late October-early November), Hemerocallis’ Stella de Oro’bud differentiation started in early June and Into dormancy in Mid-November, it has also gone through three differentiation period:undif-ferentiation (late June early mid July.), inflorescence initiation(late July early September),outerperianth initiation (mid-September to the end of October)(2) Comebined with the process of morphological differentiation, Content changes of ZRs, IAA,ABA and GA were determined with enzyme-linked immunosorbent assay(ELISA) method in roots,leaves and buds of it. The results were as follows:In the early leaves of the flower bud differentiation of Hemerocallis’Stella de Oro’, ZRs content Increased at first and then decreased. The total ABA content in undif-ferentiation gradually increased, and then decreased, the change of content in the root is greater.The content of IAA Increased in the undif-ferentiation stage,and then decreased in the inflorescence initiation,the change of GA is greater in the root, low concentrations of GA on the flower bud differentiation early is beneficial.ZRs content in the bud and root of Hemerocallis fulva dropped dramatically in the undif-ferentiation and increased gradually in the inflorescence initiation,ABA content Increased before came into inflorescence initiation stage,and then decreased in the outerperianth initiation. The content IAA in the leaves is higher than in the root. The IAA content of bud and leaves decreased in the undif-ferentiation,and then increased in the inflorescence initiation,and decreased in the outerperianth initiation.the content of GA increased in the undif-ferentiation,the change is greater in the bud.and decreased in the inflorescence initiation,and increased in the outerperianth initiation until its Period of dormancy.(3) To determinate the content of the root, bud and leaves, using SPSS16.0to analyze the relationshiip between all the Endogenous Hormones, the result showed that:In the Hemerocallis fulva the low content IAA of leaves can improve ZRs content in bud, the low content IAA in the root can improve the content of ZRs in the bud.In the Hemerocallis’Stella de Oro’, the low ZRs content in the root can improve the GA content in the bud.The low content of GA can improve the content of ZRs and IAA in the leaves.