外源AsA对土壤重金属镉胁迫下石竹(Dianthus chinensis)幼苗生长的影响  

Effects of Exogenous AsA on the Growth of Dianthus chinensis Seedlings Under Soil Cd Stress

作　　者：丁继军[1,2] 潘远智[1] 刘柿良[1] 何杨[1] 王力[1] 李丽[3] 

机构地区：[1]四川农业大学风景园林学院,成都611130 [2]长江三峡实业有限公司,湖北宜昌443002 [3]西南林业大学林学院,昆明650224

出　　处：《农业环境科学学报》2013年第8期1520-1528,共9页Journal of Agro-Environment Science

基　　金：四川农业大学双支计划

摘　　要：为探讨外源抗坏血酸(AsA)对土壤重金属镉(Cd)胁迫下石竹(Dianthus chinensis)幼苗生长的影响,采用温室盆栽试验,研究了不同浓度(0、20、40、60、80、100mg·L-1)的外源AsA处理对50mg·kg-1Cd胁迫下石竹幼苗生长的影响。结果表明:50mg·kg-1Cd显著抑制了石竹幼苗的生长,≤40mg·L-1的外源AsA可显著缓解Cd胁迫,石竹幼苗的生物量、株高、分蘖数、过氧化氢酶(CAT)、过氧化物酶(POD)、抗坏血酸过氧化物酶(APX)、单脱氢抗坏血酸还原酶(MDAR)、脱氢抗坏血酸还原酶(DHAR)、谷胱甘肽还原酶(GR)的活性,AsA和谷胱甘肽(GSH)的含量都显著高于Cd胁迫下石竹幼苗,而细胞膜透性、地上部Cd含量的产生速率以及H2O2的积累量则显著低于Cd胁迫下石竹幼苗;但随着外源AsA喷施浓度的增加,缓解效应下降,甚至产生促氧化效应。综合试验各因素表明,35～45mg·L-1的外源AsA对石竹幼苗受到的Cd毒害缓解效果较佳。In order to investigate alleviating effects of exogenous ascorbic acid（AsA）for Dianthus chinensis seedlings suffering cadmium stress, a greenhouse pot experiment was conducted to explore the effects of different concentrations（0, 20, 40, 60, 80 mg·L^-1 and 100 mg·L^-1 ） of exogenous AsA on the growth of Dianthus chinensis seedlings. Cd（50 mg·kg -1 ）significantly inhibited the growth of Dianthus chinensis seedlings. Spraying exogenous AsA（≤40 mg·L^-1 ）markedly alleviated the stress effect of Cd. Exogenous AsA significantly increased the activities of the catalase（CAT）, peroxidase（POD）, ascorbate peroxidase（APX）, monodehydroascorbate reductase（MDAR）, dehydroascorbate reductase（DHAR）and glutathione reductase（GR）. Compared with Dianthus chinensis seedlings under Cd stress, exogenous AsA also significantly increased the biomass, plant height, number of tillers, and the contents of AsA and GSH. Exogenous AsA markedly reduced the cell membrane permeability, the shoots Cd content, production rates and accumulative amount of H2O2 . However, the alleviating effect of exogenous AsA was showed as quadratic curve. With higher concentration, the exogenous AsA showed pro-oxidant effects. The present study indicated that the optimal concentration of exogenous AsA was 35～45 mg·L^-1 to alleviate the Cd stress.

关 键 词：土壤 石竹幼苗 ASA 镉胁迫 缓解效果 

分 类 号：X503.233[环境科学与工程—环境工程]