印楝幼苗对不同水分和光照条件的生理生态学响应  

Ecophysiological Responses of Azadirachta indica Seedlings to Different Water and Light Conditions

作　　者：孙恒 张燕平[1] 王友琼 吴疆翀[1] 彭兴民[1] 郑益兴[1] SUN Heng;ZHANG Yanping;WANG Youqiong;WU Jiangchong;PENG Xingmin;ZHENG Yixing(The Research Institute of Resources Insects,Chinese Academy of Forestry,Kunming,Yunnan 650224,China;Nanjing Forestry University,Nanjing,Jiangsu 210037,China)

机构地区：[1]中国林业科学研究院资源昆虫研究所,云南昆明650224 [2]南京林业大学,江苏南京210037

出　　处：《热带作物学报》2020年第11期2245-2252,共8页Chinese Journal of Tropical Crops

基　　金：国家自然科学基金项目(No.31770669)。

摘　　要：为了揭示印楝幼苗生长及代谢对不同水分和光照条件的响应规律,以0.5年生印楝半同胞家系实生苗为材料,设置4个水分水平(分别占田间持水量的60%~65%、40%~45%、30%~35%和20%~25%)与3个光照水平(分别是自然光照的100%、75%和50%)共12个组合的盆栽试验,分析不同水分及光照条件下生长指标、形态指标、生理指标及印楝素含量的变化情况。结果表明,自然光照、田间持水量为60%~65%的条件更有利于印楝幼苗的生长,干旱胁迫和遮光对印楝苗高、地径、生物量以及叶片发育均会产生抑制作用,且遮光的抑制程度明显大于干旱;在干旱胁迫条件下,印楝可通过大量合成可溶性蛋白质、游离脯氨酸及可溶性糖等初生代谢产物以及增加根茎比来提高植株干旱适应能力;在遮光条件下,印楝主要初生代谢产物可溶性蛋白质、可溶性糖、游离脯氨酸的合成受阻,其次生代谢产物印楝素的积累减少;在重度干旱胁迫条件下,遮光在一定程度上可以缓解干旱对印楝幼苗生长带来的不利影响;干旱和遮光的交互作用遵循“促进理论”,不支持“独立影响理论”。研究表明,印楝幼苗在生长过程中表现出较大的干旱适应范围及较强的光照依赖性。因此,在幼苗培育过程中要尽可能提供最大光照强度。此外,充足光照条件下适当干旱胁迫有利于印楝初生代谢产物与次生代谢产物的积累,这可作为生产上提高印楝素含量的一个潜在措施。In order to reveal the response of Azadirachta indica seedling growth and metabolism to different water and light conditions,a greenhouse pot experiment covering twelve combinations with four water levels(60%–65%,40%–45%,30%–35%and 20%–25%of field capacity,respectively)and three light levels(100%,75%and 50%of full sunlight,respectively)was set up to analyze the indicators of growth,pattern,physiological and the content of azadirachtin.The results showed that natural light and field capacity of 60%–65%were more favorable for the growth of A.indica seedlings while the height,diameter,biomass and the growth of leaves of A.indica seedlings were inhibited by drought stress and shading,and the inhibition degree of shading was significantly higher than that of drought.Under drought stress conditions.A.indica could improve drought adaptability by increasing the root--stem ratio and synthesizing a large number of primary metabolites,such as soluble proteins,free proline and soluble sugars and so on.Under shading conditions,the synthesis of soluble protein,free proline and soluble sugar were blocked;meanwhile,the content of azadirachtin was reduced.Under severe drought stress,shading could alleviate the negative effects of drought on the growth of A.indica,which followed the above-ground facilitation hypothesis and didn’t support the independent influence theory.It was concluded that A.indica had a wide range of drought adaptation and strong dependence of light in the growth stage of seeding;therefore,the maximum intensity of the light should be provided during seeding breeding.In addition,proper drought stress under sufficient light conditions was beneficial to the accumulation of primary and secondary metabolites in A.indica,which could be a potential measure to increase the content of azadirachtin in production.

关 键 词：印楝 遮光 干旱胁迫 生长 印楝素 

分 类 号：S792.23[农业科学—林木遗传育种]