土壤微藻对盐胁迫的响应及其对盐渍化土壤的改良作用

Response of Soil Microalgae to Salt Stress and Its Improvement Effect on Salinized Soil

土壤盐渍化已成为世界性环境问题.为探究盐渍化土壤生物改良新技术,利用从新疆盐渍化土壤表层生物结皮中筛选的一株微藻,通过室内模拟实验,研究了该藻的耐盐性能及其对盐碱土的改良作用.结果表明:该藻具有较高的耐盐性,能够在1 mol/L NaCl溶液中存活并生长;盐胁迫降低了微藻光合色素的含量,表现出明显的梯度效应;经过18 d的培养,0.5 mol/L,1.0 mol/L,1.5 mol/L NaCl处理组中可溶性盐分别下降16.99%,9.23%,3.27%;将土壤微藻接种在高盐碱土表层,初始叶绿素a为3μg/cm^(2),5μg/cm^(2),8μg/cm^(2)土壤的实验组,经过20 d培育后,土壤含水率分别增加了29.41%,38.29%,39.54%,胞外聚合物(EPS)分别增加了82.84%,86.04%,116.06%.说明土壤微藻具有降低可溶性盐分,控制土壤盐分运移,以及保持土壤水分的作用.该研究为土壤藻改良盐渍化土壤提供重要的理论依据.

Soil salinization has become a worldwide environmental problem.In order to explore the new biological technology for salinized soil improvement,laboratory simulation experiments were carried out in this study,in which an indigenous microalgae isolated from the biological soil crust of salinized soil in Xinjiang was used to explore the salt tolerance of the algae and its effect on saline-alkali soil.The results show that the microalgae had high salt tolerance to grow in 1 mol/L NaCl solution.The synthesis of algal photosynthetic pigments was inhibited by salt stress with obvious gradient effect.After 18 d incubation,the contents of the soluble salts in 0.5 mol/L,1.0 mol/L,1.5 mol/L NaCl treatment groups decreased by 16.99%,9.23%,and 3.27%,respectively.The soil microalgae were inoculated and cultivated on the surface of high salinealkali soil.The experimental groups with initial chlorophyll a of 3μg/cm^(2),5μg/cm^(2)and 8μg/cm^(2)soil,the soil moisture content increased by 29.41%,38.29%and 39.54%,and extracellular polymers(EPS)increased by 82.84%,86.04%,and 116.06%,respectively.These results indicate that soil microalgae can reduce soluble salt,control soil salt transport,and maintain soil moisture.This study provides an important theoretical basis for saline soil improvement by soil microalgae.