Changes in Endogenous Hormones Content and Effect of Plant Growth Regulators of Phalaenopsis during Flowering Period

Abstract:

In order to understand the effect of plant growth regulators on flowering of Phalaenopsis, the changes in endogenous hormone contents and influence of growth regulators in ‘Big Chilli’ and ‘Fullers Sunset’ were studied during flowering. The results showed that the flower bud differentiation process of Phalaenopsis included inflorescence primordium differentiation, floret primordium differentiation, calyx differentiation, petal differentiation, stamen column (stamen and carpels) and labellum differentiation. During the inflorescence primordium differentiation stage, ABA and IAA with high level inhibited vegetative growth, and the level droped after flowering and rose again after flower development. GA₃and ZR could promote cell differentiation and division. Spraying GA₃ could advance flowering and significantly increase stalk length, while spraying 6-BA could significantly improve the double stem rate of ‘Fullers Sunset’. Therefore, at the flowering stage, Phalaenopsis could be properly sprayed with growth regulators to regulate the flowering stage and the amount of flowers.

Key words:Phalaenopsis;Endogenous hormone;Plant growth regulator;Flowering