喜树愈伤组织诱导与抑制褐化的研究

Studies on the Callus Induction and Browning Inhibition of Camptotheca acumianta

[目的]筛选喜树外植体的最佳诱导培养基,研究抑制外植体及继代愈伤组织褐化的方法。[方法]以喜树的幼叶和种胚作为外植体,通过测定过氧化物酶和多酚氧化酶的活性,从外植体选择、培养基种类、激素配比、添加物的处理等方面进行愈伤组织的诱导和抑制外植体及继代愈伤组织褐化的研究。[结果]幼叶外植体的最佳诱导培养基为:SH+NAA2.5mg/L+2,4-D0.5mg/L+6-BA0.25mg/L;种胚外植体的最佳诱导培养基为:MS+2,4-D1.0mg/L+6-BA0.5mg/L。抑制幼叶外植体褐化的方法为:增加外植体大小,吹干培养基表面水分。抑制愈伤组织继代培养褐化的方法为:最佳诱导培养基附加30mg/L抗坏血酸和5g/L活性碳;1次继代后,将质地致密的愈伤组织转移到MS培养基上培养。[结论]该研究为喜树的遗传转化和植株再生提供理论基础。

[Objective] The research aimed to screen out the optimum induction medium for Camptotheca acumianta explants and study the methods of inhibiting browning of explants and callus in subculture.[Method] With the young leaves and seed embryos as explants,through determining POD and PPO activities,the study on callus induction and inhibiting the browning of explants and callus in subculture was conducted from aspects such as explant selection,medium kinds,hormone matching and treatment of adding matte.[Result] The optimal induction medium was SH＋NAA 2.5 mg/L＋2,4-D 0.5 mg/L＋6-BA 0.25 mg/L for the explants of young leaves and MS＋2,4-D 1.0 mg/L ＋6-BA 0.5 mg/L for the explants of seed embryos.The way to inhibit the browning of young leaf explants was to enhance explants sizes and dry the water on the surface of medium.The way to inhibit the browning of callus in subculture was to supplement 30 mg/L Vc and 5g/L AC into the optimal induction medium or to transfer the compact callus to MS medium after the first subculture.[Conclusion] This study provides theoretcal base for genetic transformation and plant regeneration of C.acumianta.