提高棉花抗盐性是干旱区盐渍化棉田生产面临的主要问题。通过水培和小区试验比较研究了盐分胁迫下 Si、Se-Fa、Fa-Ni、Se-Fa-Ni、Si-Se-Fa-Ni等抗逆因子及其组合对棉花干物质量、根系体积与活力、叶片MDA和Pro含量、叶片抗氧化酶活性及棉花体内盐分离子含量与离子渗透平衡的影响。结果表明，不同抗逆因子组合处理较CK可显著减轻盐胁迫对棉花生长的抑制，棉苗地上部干物质量、根系干物质量、根系体积和活力分别增加69%~148%、89%~190%、88%~137%、187%~400%。抗逆因子组合显著提高了棉花叶片抗氧化酶活性，与 CK 相比，SOD、POD、CAT、APX 活性增幅分别为11%~54%、11%~77%、13%~48%、30%~127%，而MDA和Pro含量则分别降低12%~48%和37%~49%。不同抗逆因子组合可明显降低棉花对Na+、Cl-的吸收，各组合处理的棉花体内Na+、Cl-含量较CK分别降低8%~28%和10%~24%，而K+/Na+比值和Ca2+/Na+比值则分别提高71%~168%和72%~164%（水培试验），且小区试验也得到相似结果。总之，不同抗逆因子组合可提高盐胁迫下棉花干物质量和抗氧化酶活性，阻止盐分胁迫下有害物质的积累，并通过降低盐分离子含量和提高离子比例平衡，从而提高棉花耐盐能力，其中Se-Fa-Ni和Si-Se-Fa-Ni作用效果最佳。%Improving the resistance of cotton to salt stress is the great challenge for cotton industry in saline soil in arid area. In this study, hydroponic and plot experiments were carried out to investigate the effects of silicon, selenium, fulvic acid, nitrapyrin, so-called stress resistance substances, and their combinations of Se-Fa, Fa-Ni, Se-Fa-Ni, Si-Se-Fa-Ni on cotton biomass, root volume, root activity. Meanwhile, cotton leaf antioxidant enzyme activities, including SOD, POD, CAT, APX, and both MDA and Pro were determined. Moreover, salty ions of Na+ and Cl- in cotton plant as well as the ratios of Ca2+/Na+ and K+/Na+ were also measured. The objectives of this study were to (1) explore the effectof stress-resistance substances and its combinations on increasing the ability of cotton plant resistantto salt stress, (2) screen out the optimizing combination treatment to alleviate the injury of salt stress on cotton growth. Results showed that all combination treatments significantly relieved the salt stress on cotton plant growth. For instance, compared with CK, cotton above-ground and root dry matter, root volume and activity increased by 69%~148%, 89%~190%, 88%~137% and 187%~400%, respectively. Moreover, it was found that different combination treatments exhibited a significant effect on decreasing the salt stress to cotton enzyme activity. For instance, enzyme activities of SOD, POD, CAT, APX significantly increased by 11%~54%, 11%~77%, 13%~48% and 30%~127% relative to CK, respectively. In addition, it was observed that MDA and Pro content of cotton leaves significantly decreased by 12%~48% and 37%~49%, respectively, across all combination treatments in compared with CK. Furthermore, different combination treatments presented an obvious effect on decreasing salty ions uptake in cotton plant. For example, the salty ions contents of Na+ and Cl- in combination treatments were 8%~28% and 10%~24% lower than those in CK. On the other side, the ratios of K+/Na+ and Ca2+/Na+ were 71%~168%, 72%~164% greater in combination treatments than that in CK (hydroponic experiment). Similar result was also observed in field experiment. From our findings, the conclusion can be drawn that combinations of silicon, selenium, fulvic acid, nitrapyrin exerted a significant role on alleviating the injury of salt stress on cotton. Cotton biomass and antioxidant enzyme activity were largely increased with combination treatments. Meanwhile, combination treatments significantly decreased the contents of salty ions and harm substances in cotton, as a consequent, the resistance of cotton to salt stress substantially improved by combination treatments, and Se-Fa-Ni and Si-Se-Fa-Ni treatments were identified as the optimizing combinations.
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