Abstract:

To study the dynamic changes of endogenous hormones of Phalaenopsis amabilis ‘Green Bear’ during the process of flower induction, the healthy and mature P. amabilis ‘Green Bear’ of 2 years was used as the test material to determine the contents of auxin (IAA), gibberellin (GA), abscisic acid (ABA) and zeatin riboside (ZR) at 0, 15, 30 and 45 days of the flower bud differentiation stage, the stalk period, the bud period and florescence. The results showed that during the flower bud differentiation period 15-45 d, IAA and GA decreased significantly, and reached the lowest value during the flower bud differentiation period at 45 d, IAA and GA rise rapidly during the stem picking period and reached the maximum at 95 d, which were higher than the IAA and GA content in other periods greatly, and then both decreased from 195 to 240 days during flowering period. ABA and ZR increased significantly at the flower bud differentiation period 15 d, and the ABA content decreased during the stemming period, while ZR did not change significantly, and then both increased in the budding stage and the flowering stage from 0 to 45 days, then reached the highest value at flowering stage 240 d, respectively, which were 3.2 times and 2.97 times as much as the content at flower bud differentiation stage 0 d. Therefore, it is concluded that the changes of endogenous hormones play a significant role in regulating the development of the floral organs and flower bud differentiation of P. amabilis ‘Green Bear’. Low concentrations of IAA, GA and high levels of ABA and ZR can promote the differentiation of the flower buds of P. amabilis ‘Green Bear’, while high concentrations of IAA, GA and ZR are conducive to the pedicel elongation of the P. amabilis ‘Green Bear’.

Key words: Phalaenopsis amabilis, Flower Forcing, Endogenous Hormones, Auxin, Dynamic Change