3种耐盐植物对滨海盐土化学性质及微生物群落结构的影响

为探讨耐盐植物种植对滨海盐土化学性质及微生物群落结构的影响，在滨海盐土环境下，以种植耐盐植物费菜（Sedum aizoon L.）、田菁（Sesbania cannabina（Retz.）Poir.）、蒲公英（Taraxacum mongolicum Hand.-Mazz.）的样地和未种植植物的裸地土壤（CK）为研究对象，采用土壤农化分析技术和磷脂脂肪酸（PLFA）生物标记法，对土壤化学性质、微生物群落结构及多样性进行分析。结果表明，与裸地比较，种植植物样地土壤电导率和速效钾含量均显著下降，分别下降了20.26%~57.21%和23.42%~37.80%；而有机质含量和有效磷含量显著升高，分别升高了39.16%~53.01%和106.48%~259.92%。种植植物样地土壤中PLFA种类明显增加，微生物群落也有所改变，3个植物样地土壤中总PFLAs含量和革兰氏阴性菌、放线菌、AM真菌、真核生物、真菌PFLA含量显著升高，分别升高21.53%~103.32%、4.96%~63.37%、82.91%~222.72%、50.00%~160.25%、32.05%~268.59%、19.39%~454.77%；真菌/细菌（F/B）PFLA含量也显著升高1.00~6.50倍，而革兰氏阳性菌PFLA含量和革兰氏阳性菌/革兰氏阴性菌（G⁺/G^-）PFLA含量却显著下降，分别下降了48.06%~57.78%和59.77%~68.68%。此外，种植植物样地土壤微生物群落结构多样性也明显提高。研究表明，种植费菜和蒲公英可以降低滨海盐土土壤电导率，有利于土壤有机质的积累，同时其促进多种微生物的繁殖，可有效改善滨海盐土的微生态环境。

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.