Effect of Plant Growth Regulators on Seed Germination and Development of Protocorm and Seedling of Phalaenopsis amabilis (L.) Blume (Orchidaceae)

Phalaenopsis amabilis (L.) Blume is economically ornamental species of epiphytic orchids, considered for its evergreen and clustered foliage and pendulous racemes containing several yellow-green flowers. Conventional propagation of Phalaenopsis amabilis (L.) Blume restricted by unsatisfactory rhizogenesis of shoot cutting or germination problems of lack of endosperm and low seed viability. In order to investigate the effects of some plant growth regulators on seed germination and development of protocorm and seedling of Phalaenopsis amabilis (L.) Blume disinfected capsules (21 wap) was longitudinally cutted by scalpel and its content were immediately transferred to test tube containing about 30ml MS medium supplemented by different concentration and combinations of NAA, 2,4-D and BAP. The highest value of germination percentage (83.75%) was occurred in NAA (1.5mgl-1) or combination of BAP (0.5mgl-1) + NAA (0.5mgl-1) on after/during25thday. Plant growth regulators highly affected the initiation time of protocorm formation and shortest time (53.50 days) was recorded in MS medium supplemented by NAA (1mgl-1) + BAP (1mgl-1). The best time (157.50 days) for seedling development was observed in NAA (1mgl-1) + BAP (1mgl-1) and 2, 4-D (0.5mgl-1) + NAA (1mgl-1) combination treatments.