遮光对南方红豆杉生长及紫杉醇含量的影响

Effects of shading on Taxus chinensis var. mairei growth and its taxol content

通过设计1年以上的长期遮光处理,对南方红豆杉(Taxus chinensis var.mairei)当年生幼苗、3年生和5年生幼株的生长及5年生幼株不同遮光处理后针叶中紫杉醇和其前体(10-脱酰基巴卡丁Ⅲ)含量进行了测定。结果表明,光照是影响红豆杉幼苗和幼株生长的一个重要环境因子,当年生南方红豆杉幼苗必须在荫蔽环境下才能保证高的成活率和健康的生长态势,对于3龄红豆杉幼株,全光照下,50%左右的红豆杉幼株死亡,对于5龄南方红豆杉植株,30%遮光率下有利于其健康生长;5年生南方红豆杉幼株全光照处理下的植株针叶中紫杉醇和10-脱酰基巴卡丁Ⅲ含量高于其他光照条件下的植株。南方红豆杉幼株针叶紫杉醇和10-脱酰基巴卡丁Ⅲ的最佳积累光照条件与其最适宜的生长发育光照环境并不完全平行。

The growth of 1 -, 3-, and 5-year-old seedlings and young trees of Taxus chinensis vat. mairei were studied under more than one year shading, and the contents of taxol and its precursor （ 10-deacetylbaccatin Ⅲ ） in 5-year-old young trees of T. chinensis var. mairei were determined under different shading treatments. Light was one of the important environmental factors affecting the growth of young T. chinensis var. mairei individuals. Only under shading, 1-year-old seed- lings grew up healthily and had a high survival rate ; under full light, about 50% of 3-year-old young trees died; while 30% shading was suitable for the healthy growth of 5-year-old young trees. The contents of taxol and 10-deacetylbaccatin Ⅲ in 5-year-old young trees were higher un- der full light than under shading treatments. Different ages of T. chinensis var. mairei individuals required different shading conditions to maintain their healthy growth. For T. chinensis var. mairei, the most appropriate light condition for the biosynthesis and accumulation of taxol and 10- deacetylbaccatin Ⅲ was not fully identical with the most suitable light condition for growth.