金釵石斛原球莖誘導試管開花研究

摘 要：以金釵石斛原球莖為原材料，在培養基中添加BA、TDZ和ABA誘導花芽發生，探討了金釵石斛的試管開花過程，優化了其提早開花體系。結果表明：單獨添加BA（0.2～2.0 mg/L）和低濃度的TDZ（0.02～0.10 mg/L）處理不能形成花芽。TDZ濃度提高到0.20 mg/L，開始有花芽形成，且花芽誘導率隨TDZ濃度的升高而升高，2.0 mg/L TDZ處理達到最大值26.7%。添加ABA預處理可以顯著提高花芽誘導率，1 mg/L ABA對花芽誘導效果更好。ABA預處理15 d后轉入TDZ誘導培養基中，花芽誘導率隨TDZ濃度的提高而提高， 2 mg/L TDZ處理達到最高值76.7%。試管中開花植株莖葉不發達，花芽長度和開花直徑均顯著小于正常花，有少部分能夠正常開放，花期持續2～3周。試驗中金釵石斛從種子萌發到試管開花歷時5個月，營養生長所用的時間縮短至正常生長的1/6。

關鍵詞：金釵石斛；原球莖；試管開花；TDZ

中圖分類號：Q943.1 文獻標識碼：A 文章編號：1006-060X（2023）06-0034-04

Abstract：In this study， in vitro flowering of Dendrobium nobile from protocorm-like bodies induced by BA or TDZ and ABA was explored， and the early flowering system was optimized. The results were as follows： BA alone couldn't induce floral buds formation in the test range （0.2-2.0 mg/L） among 4 months， and a small dose （0.02-0.10 mg/L） of TDZ couldn't either. When TDZ concentration was increased to 0.20 mg/L， floral buds began to form， meanwhile the initiation rate of floral buds increased with the increasing of TDZ concentration， reaching the maximum （26.7%） at 2.0 mg/L of TDZ. On the other hand， a remarkable promoting effect of ABA pretreatment on floral bud induction was observed， especially 1 mg/L of ABA led to a higher induction rate. When the protocorms were first cultured on ABA-containing （1 mg/L） medium for 15 d and then transferred onto TDZ （2 mg/L） medium， it obtained the highest rate of flower formation （76.7 %）. Growth of these in vitro miniature plants was restricted so that most of their stems and leaves were undeveloped， and their floral bud length and flower diameter were significantly smaller than those of normal flowers， of which a small part could flower normally. The flowering period could last 2-3 weeks. We use protocorms as starting materials， in vitro floral buds were observed about five months after seed germination. The time taken for vegetative growth in vitro was shorten to 1/6 of that in greenhouse， providing theoretical reference for the induction of Dendrobium in vitro flowering and the breeding of new varieties.

Key words： Dendrobium nobile; protocorm; in vitro flowering; TDZ

花的形成是高等植物所特有的一種生理現象，開花啟動的整個生理學過程是十分復雜的，因此至今整個開花過程的機制仍不十分明確。許多內在和環境的因子都會影響開花過程，但在很大程度上，這些因子都是通過影響到植物的內源激素水平而調節花的發端和發育的[1]。在自然條件下，蘭花對生長環境要求苛刻，而且從種子到開花需要很久的時間，這主要是由于蘭花的幼年期比較長，達30個月[2]，幼年期不能進行開花結果。利用組織培養的方法，縮短營養生長向生殖生長轉變的年限，這樣一個體系的建立不僅為研究蘭花的開花啟動和發育提供了一個模式系統，同時也使得人們可以對蘭花的開花性狀進行早期鑒定，縮短育種周期，減少工作量。……