Studies On Flower Bud Differentiation And Development Of Eulophia Flava

Eulophia flava, a kind of wild orchid. As an excellent ornamental plant, it is appropriate for garden landscaping and material of cut flower. The large, gorgeous, stylish flowers endow itself with great potentiality to be exploited, however its flowering period is confined at late spring and early summer which is period of slack sales, the price of its cut flower is impacted. If the flowering period is advanced to selling seasons-New Year’s Day or Spring Festival, its commodity value would be increased considerably, and development of the industry will be stimulated. Therefore, it is necessary to do some research on technology of adjusting the flowering period of E. flava. As relevant research of blossoming physiology of E. flava hasn’t been reported, the flowering mechanism isn’t clear, thus, the aforementioned research do has significant sense on research of differentiation of flower bud.In this article, observing morphological development of bud differentiation of E. flava through paraffin section, evaluating physiologic and biochemical items such as soluble sugar, soluble protein, nucleic acid and endogenous hormones at various stages during process of bud differentiation, had been investigated and inquired process of morphological development of bud differentiation of E. flava and corresponding physiological changes. This research will provides theory basis for the adjustment of florescence of E. flava.Conclusion was got as follows:1. Bud differentiation of E. flava had already completed at the time when bud blossoms and before exposed on the ground. Differentiation of organs had completed when the bud exposed on the ground. The progress of bud differentiation was mainly divided into six stages:first. initial differentiation phase; second, inflorescence primordium differentiation phase; third, flower primordium differentiation phase; fourth, sepal primordium differentiation phase; fifth, petal primordium differentiation phase; sixth, column and pollinia differentiation phase.2. Soluble sugar and soluble protein content in pseudobulb reduced initially and then increased in the process of bud differentiation. Changes of C/N value of pseudobulb showed that high C/N value was favorable to the commencement of bud differentiation.3. General trend of nucleic acid in pseudobulb went up and decreased in late period of bud differentiation indicated that high level of nucleic acid was favorable to the process of bud differentiating; comparative lower nucleic acid was favorable to the completion of bud differentiation.4. Changes of endogenous hormones during the process of bud differentiation indicated that relatively high content of IAA and ABA was conducive to the flower buds breeding, and relatively lower content of IAA and ABA was conducive to the formation of flowers. GA and ZR might be disincentive to the early stage of bud differentiation but promoting bud formation at the late stage.