THE EFFECT OF DIFFERENT GROWTH MEDIA, CARBON SOURCE AND PGRs ON DENDROBIUM BROGA GIANT ORCHID’S PROTOCORM-LIKE BODIES (PLBs) PROLIFERATION SUPPORTED WITH SEM AND TEM ANALYSIS

摘要

Dendrobium Broga Giant (Dendrobium Bobby Messina × Dendrobium Superbiens) is a new orchid hybrid in Malaysia.The aim of this study was to investigate the effect of different growth media, carbon sources and PGRs on DendrobiumBroga Giant orchid’s protocorm-like bodies (PLBs) proliferation supported with SEM and TEM analysis. The PLBs werecultured on different strength of semi-solid and liquid MS medium and the proliferation rate was recorded based on the freshweight basis. The maximum PLBs proliferation (12.31% ± 0.57) was obtained in ? MS semi-solid medium. PLBs werecultured on ? MS semi-solid media supplemented with different sucrose concentrations (0, 10, 20, 30 & 40 g.L-1). Thehighest proliferation rate of PLBs (15.48% ± 1.20) was recorded from ? MS supplemented with 20 g.L-1 sucrose. Differentconcentrations of BAP (0, 0.5, 1.0, 2.0 mg.L-1) and NAA (0, 0.5, 1.0, 2.0 mgL-1) were added to ? MS semi-solid medium.Combinations of 1.0 mg.L-1 BAP and 0.5 mg.L-1 NAA produced higher PLBs proliferation. Micromorphological studies bySEM and TEM displayed trichome, leaf primordial, stomata, various sizes of mitochondria, vacuoles, different shapes ofchloroplast were found in PLBs which ameliorated the slow proliferation nature of plantlets.