【作者】 马梅芳；

【导师】 阎秀峰； 王洋；

【作者基本信息】 东北林业大学 ， 生态学， 2003， 硕士

【摘要】 对喜树而言，喜树碱是一种重要的化学防御物质。本项研究较为系统地测定了从喜树种子萌发到幼苗形成过程中喜树碱含量的动态变化过程。从喜树种子萌发到幼苗形成，胚乳中的喜树碱含量始终处于较高的水平。其他各部位的喜树碱含量随发育时期而变化，除子叶是在种子萌发9～15天达到最大值外，其他各部位越是处于幼嫩期，喜树碱含量越高。其中叶片在其幼嫩时期喜树碱含量最高，甚至可以达到4‰以上。其他各部位喜树碱含量的最大值相近，为1‰左右。幼苗根中的喜树碱含量始终保持在一个较低的水平。各部位喜树碱含量的最低值也基本一致。实验结果说明，喜树种子中存在幼体化学防御模式，器官引起的差异明显弱于发育时期变化引起的差异，喜树碱在种子中的作用主要是在植物物理防御能力尚未完善时，承担着化学防御的任务。更多还原

【Abstract】 Camptothecin is an important defensive chemical in Camptotheca acuminata. We systematically analyze the variation in camptothecin during the process of seed germination, the formation of the seedling, and the development of the saplings. From the seed germination to the formation of the seedlings of C. acuminata, CPT content in endosperm was always in a really high level, while that in other parts varied with the plants development. The camptothecin content was higher in the younger tissue than in elder, otherwise that in cotyledon was highest when the seedlings were 9-15 days old. The camptothecin content were highest in youngest leaves(can be above 4‰o), and the highest contents in others parts were similarly about 1‰, but that in roots was about 0.2‰ equal to the lowest content in other parts. The results show that there is an evident juvenile defense strategy in the seeds of C. acuminata. Difference which the change causes of period is obvious weaker than development of difference that the organ causes. The role of camptothecin in seed is mainly undertaking the task of the chemical defence when the physics defence capability of the plant has not perfected yet.更多还原