Effects of 3 salt-tolerant plants on the chemical properties and microbial community structure of coastal saline soil

The aim of this study was to analyze the effects of salt-tolerant plants on the chemical properties and microbial community structure of coastal saline soil and provide a scientific basis for vegetation restoration in saline soil. Plots with coastal saline soil were planted with Sedum aizoon L., Sesbania cannabina(Retz.)Poir., and Taraxacum mongolicum Hand.-Mazz., and the control plot had only coastal saline soil. Soil agrochemical analysis technology and phospholipid fatty acid(PLFA)biomarker method were used to analyze the chemical properties and microbial community structure and diversity of the coastal saline soil. Both electrical conductivity and available potassium content of the coastal saline soil planted with the salt-tolerant plants decreased significantly by 20.26%~57.21% and 23.42%~37.80%, respectively. However, soil organic matter and available phosphorus content increased significantly by 39.16%~53.01% and 106.48%~259.92%, respectively. The types of PLFA in the sample plots planted with the salt-tolerant plants increased significantly, and the microbial community changed. The 3 sample plots planted with the salt-tolerant plants showed the PLFA content of gram-negative bacteria(G-), actinomycetes, AM fungi, eukaryotes, and fungi, and the total PLFAs increased by 4.96%~63.37%, 82.91%~222.72%, 50.00%~160.25%, 32.05%~268.59%, 19.39%~454.77%, and 21.53%~103.32%, respectively. The ratio of fungi to bacteria also increased significantly by 1.00~6.50 times, whereas the content of gram-positive bacteria(G+)and ratio of G+ to G-(G+/G-)decreased significantly by 48.06%~57.78% and 59.77%~68.68%, respectively. In addition, the diversity of the soil microbial community in the sample plots with the salt-tolerant plants increased significantly. Cultivation of Sedum aizoon L. and Taraxacum mongolicum Hand.-Mazz. can reduce the electrical conductivity of coastal saline soil, facilitate the accumulation of soil organic matter, and stimulate the reproduction of a variety of microorganisms, thereby effectively improving the micro-ecological environment of coastal saline soil