【作者】 杨晓娟；

【导师】 范国强；

【作者基本信息】 河南农业大学 ， 森林培育， 2005， 硕士

【摘要】 泡桐是我国重要的速生用材树种之一。由于其繁殖容易,生长快、材质好等优点,深受广大群众的欢迎。但泡桐丛枝病和大冠低干等问题长期以来制约着泡桐的发展。为通过植物组织培养的方法从理论上研究泡桐丛枝病,以前有人利用带腋芽的茎段的途径以及器官间接发生途径和体细胞胚胎发生途径建立了泡桐的体外植株再生系统,但这些研究工作更主要集中在激素的方面研究。 为了进一步优化泡桐植株再生条件,从而为开展泡桐基因工程和细胞工程和培育泡桐新品种等工作奠定基础,本文以兰考泡桐无菌苗叶片为外植体,研究了不同外源物质、光周期和低温处理对兰考泡桐叶片芽诱导的影响,现将结果归纳如下。 在甘油和蔗糖的所有组合中,蔗糖浓度为20g·L^-1时,诱导率最高,达到了64.15%,蔗糖对兰考泡桐叶片的芽诱导的影响极显著,甘油对褐化率的影响显著,从获得较高兰考泡桐芽诱导率来看,蔗糖好于甘油,蔗糖的最适浓度为20g·L^-1。 在附加PVP和Vc的培养基上,当PVP浓度为7g·L^-1时,芽诱导率最高,达到了81.58%,PVP对兰考泡桐叶片的芽诱导的影响极显著,Vc对芽诱导的影响显著而且对褐化率的影响极显著。综合考虑褐化率和芽诱导率,较为适宜的芽诱导培养基添加物为PVP,培养基中PVP的最适浓度为7g·L^-1。 适宜浓度的DTT能够促进兰考泡桐叶片芽的诱导,芽诱导率最高的DTT浓度是10mg·L^-1。 在柠檬酸和AgNO₃的实验中,柠檬酸和AgNO₃对兰考泡桐叶片的褐化和芽诱导的影响均表现为极显著,当柠檬酸浓度为0.15g·L^-1时,芽诱导率最高（74.07%）。兰考泡桐叶片的较好的抗褐化剂为柠檬酸,其适宜浓度为0.15g·L^-1。 在附加10.00mg·L^-1DTT的培养基中,同时加入AgNO₃和柠檬酸的组合,芽诱导率比对照低,因此,这三者不适合结合使用。 光周期和不同黑暗处理时间对兰考泡桐叶片芽诱导的试验表明,不经过黑暗处理的兰考泡桐叶片有利于芽的诱导,且在光周期24h时芽诱导率最高。 4℃低温处理条件下,连续光照2d,全光照最有利于兰考泡桐叶片芽的诱导,芽诱导率可达100%。 根的诱导率与光周期无关,但光周期影响根的生长。更多还原

【Abstract】 Paulownia is a kind of popular,fast-growing trees which is of good quality,but those problems, including withes broom,large crown and short main stem and so on,keep Paulownia from further development.with the boom of modern science and technology,gene engineering and cell engineering provide effective methods to solve these problems.Researches about in vitro plant regeneration is basic for application of plants modern technology, in vitro plant regeneration has two ways, which are organ genesis and somatic embryogenesis.Setting up the system of in vitro plant regeneration of Paulownia lay soud foundation for gene engineering, cell engineering and cultivation of new cultivar of Paulownia.from our experiment of the system o ptimization of plantlets regeneration from Paulownia leaves by exogenous substance and culture conditons ,we got such following conclusions:1. Comparing the two kinds of carbon souces ,we came to the result that for the plant regeneration from Paulownia elongate leaves, sucrose was better than glycerol, and its corresponding optimal concentration is 20g·L^-1,and its corresponding bud induction rate is 64.15%.2. Both PVP and Vc could accelerate the plant regeneration of Paulownia elongate leaves,but their combinative effect was not better than their respective effect,for Vc,its optimal concentration was 0.05mg·L^-1, its bud induction rate was 69.23%.while the PVP optimal concentration was 7 g·L^-1, its bud induction rate was 81.58%.3. DTT was also good for the plant regeneration of Paulownia elongate leaves,and its optimal concentration was 10mg·L^-1, the higher or lower concentration did more harm than good,its bud induction rate was 65.72%.4. Compared with AgNO₃, citric acid was more effective to regenerate plantlets from Paulownia elongate leaves,and the citric acid best concentration was 0.15g·L^-1 in all the tested concentrations,its corresponding bud induction rate is 74.07%.5. With the existence of 10mg·L^-1 DTT in the media, the effect of PVP and Vc is different from the above,the best combination is AgNO₃ 0.015 g·L^-1 和 DTT 10.00mg·L^-1,its corresponding bud induction rate is 65.22%.更多还原