外源亚精胺对盐胁迫下黄瓜幼苗耐盐性的影响

摘要

In order to explore the effect of different concentrations of extraneous spermidine on the salt tolerance in cucumber seedlings under salt stress,"JinChun No.4" was used in the artificial climate incubator with matrix culture methods,and different concentrations of extraneous spermidine (0,50,100,150,200,250 mg/L)were applied at cucumber seedlings under 200 mmol/L NaCl stress to study the changes of the cucumber seedlings growth,chlorophyll content,malondialdehyde(MDA)content,relative conductivity,soluble sugar content,and sucrose content.The results indicated that a certain concentration of extraneous spermidine increased significantly the seedling morphological indicators and chlorophyll content; the treatment of 100 mg/L extraneous spermidine decreased significantly the content of MDA in seedling leaves,the largest drop can reach to 47.4％; the treatment of 100 mg/L extraneous spermidine decreased significantly the relative conductivity; a higher concentration of extraneous spermidine could significantly improve the content of soluble sugar,a lower concentration of extraneous spermidine could significantly improve the content of sucrose content.Based on the physiological indices,it could be concluded that a certain concentration of extraneous spermidine could significantly relieve the salt injury and improve salt tolerance of the cucumber seedlings.%为探讨盐胁迫下不同浓度外源亚精胺处理对黄瓜幼苗耐盐性的影响,以“津春四号”黄瓜为试验材料,在人工气候培养条件下,采用基质培育法研究了不同浓度(0、50、100、150、200、250 mg/L)外源亚精胺对200 mmol/L NaCl胁迫条件下的黄瓜幼苗各项形态指标和叶绿素含量、丙二醛含量、电解质渗透率、可溶性糖含量以及蔗糖含量等生理指标的影响.结果表明:盐胁迫下,经外源Spd预处理的黄瓜幼苗各项形态指标和叶绿素含量显著升高；100 mg/L的Spd处理可显著降低叶片丙二醛含量,最大降幅可达47.4％；100 mg/L Spd处理浓度可显著降低黄瓜幼苗相对电导率；较高浓度的Spd处理,可显著提高幼苗可溶性糖含量,而较低浓度的Spd处理,可提高幼苗蔗糖含量.综合各项生理指标,盐胁迫下Spd处理可显著缓解黄瓜幼苗的盐害,提高幼苗的抗盐性.