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

Effects of Flower Stalk Stage, Nodal Bud Position and 6-Benzyladenine Concentration on the Shoot Induction in Micropropagation of Phalaenopsis Flower Stalk Node Explants

以蝴蝶蘭栽培種Phalaenopsis Sunrise Spring 'SRM153'不同花梗發育時期之花梗芽為培植體，培養於含有VW基本鹽類、20%椰子水、5mg•L^(-1)6-benzyladenine（BA）與0.2%活性碳之培養基。結果在七個花梗發育期中以第二期（stage 2），即可見第一朵花分化期之花梗芽有較高之芽體誘導反應率（90%-100%），且所誘導出之芽體具有良好的生長特性。花梗芽在培養過程中可誘導長出營養芽、花梗芽、擬原球體（Protocorm-LikeBodies, PLBs）與休眠芽等四種形式之芽體。以蝴蝶蘭Phal.（Taisuco Snow×Wataboushi）'T343'花梗發育stage 2之花梗芽培養於含有不同BA濃度的1／2MS培養基中，結果於低濃度的BA（1.25 mg•L^(-1)）即可誘導出芽體。隨著BA濃度的提升，每一花梗節獲得的平均芽體數亦隨之增加。當BA濃度提高至10.0 mg•L^(-1)時，可打破所有花梗節位的休眠性。頂芽培植體在低BA濃度處理下，只能誘導出單一芽體，且芽體較為瘦小，短縮莖較不明顯。接近花序之花梗芽有先誘導出花梗而後再長出營養芽體的現象。 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.