准噶尔盆地南缘两种典型禾本科植物根鞘土壤微生物群落功能多样性

以准噶尔盆地南缘两种禾本科植物的根鞘与其外围土壤为研究对象,采用Biolog-ECO微平板检测法对土壤微生物群落功能多样性进行了研究。结果表明:两种植物根鞘土壤的有机质、全氮、速效氮和速效钾均高于根鞘外围土壤;两种禾本科植物根鞘土壤的微生物平均颜色变化率(AWCD)、香农多样性指数、均匀度指数、优势度指数和丰富度指数均高于根鞘外围土壤;两种植物根鞘土壤微生物主要利用的碳源类型为羧酸、糖类和聚合物,其中芨芨草根鞘微生物是以利用羧酸、糖类、聚合物和氨基酸类物质为主,羽毛针禾根鞘土壤微生物是以利用糖类、氨基酸和聚合物为主;微生物平均颜色变化率与Shannon多样性指数、均匀度指数、速效钾和全氮呈显著相关性,除了全钾以外,与其余的土壤理化指标均存在正相关性。总而言之,根鞘结构改善了微生物的生存环境,提高了土壤微生物群落功能多样性,从而增强了缓冲外界不利影响的能力。

Rhizosheath soil microbial functional diversity of two typical Gramineae plants in the southern margin of the Junggar basin

The present study investigated two Gramineae species growing in both rhizosheath and non-rhizosheath soils on the southern margin of the Junggar Basin. The Biolog-ECO microplate method was used to study the microbial community functional diversity of these species. The results showed that the organic matter, total nitrogen, available nitrogen, and available potassium in the rhizosheath of the two plant species were higher than in the non-rhizosheath soil. The average well color development (AWCD), Shannon diversity index, evenness index, Simpson index, and richness index were all higher in the rhizosheath soil than in the non-rhizosheath soil; the main carbon sources of microbes in the rhizosheath of the two plant species were carboxylic acids, polymers, and carbohydrates. The main carbon sources of microbes in the rhizosheath of Achnatherum splendens (Trin.) Nevski were carboxylic acids, carbohydrates, polymers, and amino acids. The main carbon sources of microbes in the rhizosheath of Stipagrostis pennata were carbohydrates, amino acids, and polymers. Significant correlations with the AWCD were found for the Shannon diversity index, Evenness index, available potassium, and total nitrogen. There were positive correlations with AWCD for all physical-chemical soil properties, except for total potassium. Overall, the rhizosheath enhanced the ability to alleviate negative outside influences by improving microorganism survival and increasing the microbial community functional diversity.