干旱对不同种源喜树苗木生长及叶片喜树碱产量的影响

摘要

A pot experiment in greenhouse was conducted to investigate the effect of drought stress on 1-year-old seedling growth of Camptotheca acuminata from 8 provenances. The camptothecin concentrations in leaves of the seedlings under drought stresses were determined by the ultra performance liquid chromatography ( UPLC ) and the yields of camptothecin per plant were subsequently calculated. Results showed that; The drought stress inhibited the seedling growth by decreasing the basal diameter and height increment, and decreasing total biomass of all seedlings from the 8 different provenances. The differences in the basal diameter and height increment, the total biomass, and the yield per plant were significant among different treatments and provenances ( P ＜ 0. 05 ) . Variance analysis indicated that the contents of camptothecin had significant difference among provenances and levels of soil moisture ( P ＜ 0. 05 ) , and the contents of camptothecin increased at first and then decreased in all the provenances with drought stress strengthening. Under drought stress, the yields of camptothecin per plant decreased in almost all provenances, but under light drought stress, the yields of camptothecin per plant increased in GL and NJ provenances, with the highest yield up to 27. 904 mg per plant in GL provenance. The differences in the yields of camptothecin per plant were significant among different provenances. It is concluded that GL provenance had the highest content and yield of camptothecin per plant, and especially its yield was able to be improved under light drought stress. Thus this study would provide a theoretical basis for selective breeding as well as the establishment and management of leaf-producing plantation of C. acuminata.%以长江以南8个不同种源的1年生喜树实生苗为研究对象,采用温室土培盆栽模拟干旱环境,研究干旱对不同种源喜树苗期生长的影响,同时利用超高效液相色谱测定干旱胁迫下各种源叶片喜树碱含量,计算单株叶片喜树碱产量.结果表明:干旱胁迫限制喜树苗期的生长,不同喜树种源地径和苗高的生长以及总生物量的积累均受到抑制,不同干旱处理间和种源间喜树的地径增粗、苗高增长、总生物量及叶产量等均存在显著差异(P＜0.05)；干旱对叶片喜树碱含量有显著影响(P＜0.05),且不同种源之间存在显著差异(P＜0.05),随于旱处理程度加深,叶片喜树碱含量呈先升高后降低的变化趋势；干旱导致大部分种源的单株叶片喜树碱产量降低,仅有桂林种源和南京种源的单株叶片喜树碱产量在轻度干旱胁迫下有所升高,不同种源之间存在显著差异(P＜0.05),轻度干旱下种源桂林的喜树碱产量最高,达到27.904 mg.轻度干旱可以提高喜树苗木叶片喜树碱含量,同时种源桂林在所有受试种源中均有较高的叶片喜树碱含最和产量.