花梗發育時期、花梗節位及6-benzyladenine濃度對蝴蝶蘭花梗芽微體繁殖芽體誘導之影響

Nodal explants taken from flower stalks of seven developmental stages of Phalaenopsis Sunrise Spring 'SRM153' were tested for in vitro shoot proliferation. Nodal explants were inoculated on the V5B medium (VW basal salts, B5 vitamins, 20% coconut milk, 5 mg•L^(-1) BA and 0.2% actived charcoal) for shoot induction. Nodal explants taken from stage 2, i.e. the first flower visible stage, flower stalk had the highest (90%-100%) shoot induction rate along with good growth quality. Four types of shoot differentiation (vegetative shoot, reproductive shoot, protocorm like body and dormant shoot) were observed in this study. Nodal explants taken from stage 2 flower stalk of Phal. (Taisuco Snow × Wataboushi) 'T343' were cultured on a 1/2MS basal medium containing 0.1 mg•L^(-1) NAA and various concentrations of BA. Although low level of BA (1.25 mg•L^(-1)) could induce shoot growth, the average number of shoots produced per nodal explants increased with increasing BA concentration from 1.25 to 15 mg•L^(-1). No bud dormancy was found in the nodal explants of various positions when BA concentration increased to 10.0 mg•L^(-1). The nodal position on flower stalks, had a significant influence on the type of shoot induction. An explant of the inflorescence tip could only develop into a small single shoot with short stem. Nodal explants taken from the position near the inflorescence tended to induce flower stalk before turning to vegetative shoots under low BA concentrations.