王惠珍　陆国弟　陈红刚　崔治家　杜弢　王亚丽

摘要：目的 研究成药期党参在干旱胁迫下的生理特性变化，揭示党参响应干旱胁迫的生理机制。方法 采用盆栽控水试验，设置正常供水、轻度胁迫、中度胁迫和重度胁迫4个水分处理，通过测定党参叶片相对含水量、细胞膜透性、渗透调节物质含量、抗氧化酶活性等指标，研究干旱胁迫对党参生理特性的影响。结果 随干旱胁迫程度增加，党参叶绿素a、叶绿素总含量和叶片相对含水量呈逐渐降低趋势，叶绿素b无明显变化；电导率呈先增加后降低的趋势，丙二醛含量呈先增加后降低再增加的趋势，超氧阴离子产生速率无明显变化；过氧化物酶（POD）和过氧化氢酶（CAT）活性呈逐渐增加趋势，超氧化物歧化酶无明显变化；脯氨酸含量呈先增加后降低的趋势，可溶性糖呈降低趋势，可溶性蛋白无明显变化。结论 干旱胁迫下，党参通过增加脯氨酸含量调控细胞渗透势，同时提高抗氧化酶POD和CAT活性，减轻膜脂过氧化产物对细胞的伤害。

关键词：党参；干旱胁迫；膜透性；保护酶；渗透调节物质

DOI：10.3969/j.issn.1005-5304.2018.03.016

中图分类号：R282.2 文献标识码：A 文章编号：1005-5304（2018）03-0072-05

Abstract： Objective To study the physiological characteristics of Codonopsis Radix under drought stress； To reveal the physiological mechanism of Codonopsis Radix in response to drought stress. Methods Method of pot experiment was used to set up 4 water treatments： normal water supply， mild stress， moderate stress and severe stress. Through the determination of leaf relative water content， cell membrane permeability， osmotic adjustment contents and protective enzyme activity， the effects of drought stress on physiological characteristics of Codonopsis Radix were studied. Results With the drought stress increased， the chlorophyll a， total chlorophyll content and leaf relative water content of Codonopsis Radix decreased， but chlorophyll b had no obvious change； The conductivity increased first and then decreased； MDA contents increased first and then decreased and then increased； There was no significant change in the rate of superoxide anion production； POD and CAT activity increased； SOD had no significant change； The proline content increased first and then decreased； soluble sugar decreased； soluble protein had no significant change. Conclusion Under the condition of drought stress， by increasing the content of proline to regulate cell osmotic potential， Codonopsis Radixcan increase the antioxidant enzyme activity to reduce membrane lipid peroxidation damage to cells.

Keywords： Codonopsis Radix； drought stress； membrane permeability； protective enzyme； osmotic adjustment substance

我國干旱及半干旱地区面积广，非干旱地区作物在生长季节也会发生不同程度的干旱。据不完全统计，我国每年由干旱给农业造成的损失相当于其他所有环境因子的总和[1]。目前已在柴胡、蒲公英、金钗石斛、忍冬、文冠果等药用植物上进行了抗旱特性和耐旱机制研究[2-6]。

党参Codonopsis pilosula（Franch.）Nannf.为桔梗科多年生草本植物，以干燥根入药，具补中益气、健脾益肺功效，用于脾肺气虚、食少倦怠、咳嗽虚喘、心悸气短、内热消渴等。……