氮素水平对喜树幼苗喜树碱含量的影响

Effect of nitrogen on camptothecin content in Camptotheca acuminata seedlings

目的:探讨氮素营养水平对喜树幼苗喜树碱含量的影响。方法:在温室中对砂培喜树幼苗进行5种氮素水平处理,用HPLC测定了喜树幼苗各器官中喜树碱含量,观察了幼叶中喜树碱含量的动态变化过程。结果:不同氮素水平下喜树幼苗幼叶中喜树碱含量均明显高于其他器官的(P<0.01)。喜树幼苗幼叶中的喜树碱含量在不同氮素水平下随时间进程均呈明显的单峰曲线,处理的第50天达到高峰;幼叶的喜树碱含量随氮素水平的增加而明显减小,氮素水平为4 mmol.L-1时幼叶的喜树碱含量最高(6.72‰),是16 mmol.L-1的1.1倍。结论:适宜的供氮水平对于喜树幼苗幼叶中的喜树碱含量极为重要,适当的低氮胁迫能够显著地增加喜树幼苗幼叶的喜树碱含量。

Objective： To investigate the effects of nitrogen concentration on the camptothecin （CPT）content in Camptotheca acuminata seedlings. Method： The seedlings of C. acuminata with 6 pair of leaves were subjected to five nitrogen concentrations treat-ments by sand culture in a greenhouse. The CPT content in the seedlings was determined by HPLC on the 20th, 35th, 50th, 65th and 80th day respectively. Result： The CPT content in the young leaves of C. acuminata seedlings supplied with different nitrogen concen-tration was significantly higher than that in other organs （P 〈 0.01 ）, and it showed a single peak curve with the time course, the high- est CPT content was observed on the 50th day after treatment. The CPT content in the young leaves obviously declined with increasing nitrogen concentration, and it reached the highest（6.72% ）when nitrogen concentration was 4mmol·L^-1, equal to 1.1 times that of 16mmol·L^-1 nitrogen. Conclusion： The results demonstrate that proper deficient nitrogen stress can significantly enhance CPT accu-mulation in young leaves of C. acuminata seedlings.