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Studies on the Clonal Propagation of Monopodial Orchids by Tissue Culture

1975; Japanese Society for Horticultural Science; Volume: 44; Issue: 1 Linguagem: Inglês

10.2503/jjshs.44.47

1880-358X

Michio Tanaka, Atsushi Hasegawa, Masanori Goi,

Plant and animal studies

The present studies were carried out in order to establish the method of clonal propagation by leaf tissue culture in Phalaenopsis and Vanda.1. Tissues cultured were the leaf segments of dimensions 8-10×8-10mm excised from young seedlings and matured plants of the both orchids, as well as the leaf tip of 5-7mm in length from infant seedlings of Vanda and the whole leaf of 8-10mm in length from those of Phalaenopsis.The tissues were cultured under light on agar media containing various components, and the subsequent formation of protocorm-like bodies (P.L.B.) on the explants was observed.The first external sign of cellular activity in explants was the appearance of a tiny protuberance to the tissue. The protuberance was seemed to be a primordium of P.L.B.2. It was observed that the young leaf tissue from infant seedlings of Phalaenopsis and Vanda formed the P.L.B. easily by aseptic culture. In that, the P.L.B. were formed on the adaxial surface just above the basal cut-end of the explant in 2Vanda and on the surface of adaxial side in Phalaenopsis.3. In both orchids, the proximal tissue of a leaf formed the P.L.B. more easily than the distal one.4. The ability of the P.L.B. formation was high in the explant of infant seedlings, though a low ability was observed when the explant was excised from a seedling advanced in age. The lowering of the ability with aging of seedling was shown more clearly in Vanda than in Phalaenopsis.5. The reduced ability of the P.L.B. formation in the eyplant from matured plants of Phalaenopsis can be tolerably recovered by means of etiolation of stock plant. The tissue from an unexpanded distal part of the etiolated leaf formed primordia of the P.L.B. fairly well. The primordia may develop into the P.L.B. after culturing in succession.6. The result of the morphological observation shows that the P.L.B. formed on explants may be derived from epidermal cell (or cells) or cells just below epidermis.7. As a practical medium for the P.L.B. formation, the following recipe will be recommended.Hyponex (N:P:K=7:6:19) 3.5gmyo-Inositol 100.0mgNicotinic acid 1.0mgThiamine•HCl 1.0mgNAA 5.0mgKinetin 10.0mgSucrose (Including the sucrose contained in fruit juice) 3.0%Fresh strained apple juice (or coconut milk) 100.0mlDistilled water 900.0mlpH was adjusted to approx. 5.38. The P.L.B. formed on the explants of both Phalaenopsis and Vanda was shown to grow to juvenile plants on a medium suitable for the seed germination of the orchids.