光强对喜树幼苗喜树碱含量及分配的影响

Effect of light intensity on camptothecin content and allocation in Camptotheca acuminata seedlings

喜树碱是我国特有树种———喜树中所含的重要次生代谢产物。在人工控制条件下观察了光强对喜树幼苗各器官中次生代谢产物喜树碱含量及分配的影响。轻度遮荫(相对光强为全光照的60%)处理30天和75天时叶片、茎及全株的喜树碱含量均较对照(全光照)有所提高,而根的喜树碱含量则是在全光照处理30天和重度遮荫(相对光强为全光照的30%)处理75天时较高。喜树幼苗根和茎的喜树碱产量在75天的重度遮荫处理后增加,而轻度遮荫条件下处理75天时叶片和全株有较高的喜树碱产量。光强也影响喜树碱在喜树幼苗各器官中的分配。

Camptotheein （CPT） is an important secondary metabolite in Camptotheca acuminata, native deciduous tree of south China. In the present work, under controlled conditions, the effect of light intensity on CPT content and allocation in Camptotheca acuminata seedlings was observed. When the irradiance decreased to 60% of full sunlight, CPT content in leaves, stem and the whole plant tended to increase after 30 and 75 days of treatment. CPT content in roots was higher in full sunlight after 30 days of treatment and in 30% of full sunlight after 75 days of treatment. CPT yield were enhanced in roots and stem after 75 days of treatment with the irradianee of 30% of full sunlight. For whole plant and leaves, in 60% full sunlight, CPT yield increased after 75 days of treatment. Light intensity also influenced CPT allocation in Camptotheca acuminata seedlings.