中文摘要：

在200mmol·L^-1 NaCl胁迫条件下，采用根际注射结合叶面喷洒的诱导方法探讨了不同浓度水杨酸、油菜素内酯、壳聚糖、亚精胺4种化学诱抗剂对黄瓜幼苗生长及其生理生化特性的影响．结果表明，4种化学诱抗剂在适宜浓度范围内，显著地降低了黄瓜幼苗的盐害指数和死苗率，以油菜素内酯0．01mg·L^-1降低幅度最大，比对照分别降低了63．0％和75．0％；显著地促进了超氧化物歧化酶、过氧化物酶、过氧化氢酶等保护酶活性，从而显著降低了丙二醛含量和电解质渗出率，干重含水量显著升高；促进了幼苗的形态建成，植株茎粗、展开叶数及壮苗指数显著提高，壮苗指数以壳聚糖150mg·L^-1最大，比对照提高了30．9％．说明施用适宜浓度的化学诱抗剂可以诱导黄瓜幼苗的抗盐能力，减缓盐害症状．综合作用效果依次为：油菜素内酯0．005—0．05mg·L^-1、亚精胺150～200mg·L^-1、壳聚糖100—200mg·L^-1和水杨酸50～150mg·L^-1．

英文摘要：

With root injeetion and foliar spray, this paper studied the effeets of different eoneentrations salieylie aeid, brassinolide, ehitosan and spermidine on the growth, morphogenesis, and physiologieal and bioehemical eharaeters of cucumber （ Cucumis sativus L. ） seedlings under 200 mmol·L^-1 NaCl stress. The results showed that at proper concentrations, these four exogenous chemical aetivators eould markedly deerease the salt stress index and mortality of cueumber seedlings, and the decrement indueed by 0.01mg·L^-1 brassinolide was the largest, being 63.0% and 75.0% ,respeetively. The aetivities of superoxide dismutase （SOD） , peroxidase （POD） and eatalase （CAT） increased significantly, resulting in a marked decrease of malondialdehyde （MDA） content and electrolyte leakage. The dry weight water content and morphogenesis of eueumber seedlings improved, and the stem diameter, leaf number, and healthy index increased signifieantly. All of these suggested that exogenous ehemieal activators at proper concentrations could induce the salt resistanee of cueumber, and mitigate the damage degree of salt stress. The salt resistance effect of test exogenous ehemieal activators deereased in the sequenee of 0. 005～0. 05mg·L^-1 brassinolide, 150-250mg·L^-1 spermidine, 100-200 mg·L^-1 ehitosan, and 50 - 150mg·L^-1 salicylic acid.