【背景】土壤微生物是草原生态系统的重要组成部分，在调节植物生长、促进土壤结构的形成及维持草原生态系统功能和稳定性等方面有着不可替代的作用。【目的】探究内蒙古自治区四子王旗两种不同草原中5种不同植物根际土壤微生物群落代谢功能的多样性。【方法】利用Biolog-ECO微平板法分析四子王旗荒漠草原中阿德格和格根塔拉2个样地中短花针茅、冷蒿、细叶葱、阿尔泰狗娃花和银灰旋花5种植物根际土壤微生物群落多样性特征。【结果】两种不同草原中5种不同植物根际土壤中可培养微生物数量存在显著性差异(P<0.05)，阿德格草原中短花针茅根际土壤中可培养微生物总数显著高于其他植物根际，格根塔拉草原中阿尔泰狗娃花根际土壤中可培养微生物总数显著高于其他植物；两样地不同植物根际土壤微生物的平均颜色变化率(average well color development，AWCD)均表现为格根塔拉样地高于阿德格样地，而且呈“S”型变化。培养96 h后格根塔拉草原5种植物的Shannon指数与Simpson指数高于阿德格草原，同时银灰旋花根际土壤微生物多样性指数在两个草原中差异极显著；两个草原不同植物根际土壤微生物对碳源的利用主要是氨基酸类和碳水化合物碳源，对于L-天门冬酰胺、r-羟基丁酸、L-丝氨酸和D-半乳糖醛酸等碳源的功能微生物显著富集，根际土壤微生物的AWCD和多样性指数与细菌、放线菌以及土壤微生物总数呈极显著正相关性(P<0.01)，均匀度指数与细菌、放线菌以及土壤微生物总数量呈显著负相关性(P<0.05)。【结论】不同植物根际土壤微生物对碳源的利用能力和偏好出现差异，而且根际土壤微生物数量越高，微生物碳代谢能力、微生物群落多样性越丰富。
[Background] Soil microbe is an important part of grassland ecosystems, and it plays an irreplaceable role in regulating plant growth, promoting the formation of soil structure, and maintaining the function and stability of grassland ecosystems. [Objective] To explore the diversity of microbial community metabolic function in rhizosphere soil of five different plants in two different grasslands in Siziwang Banner of Inner Mongolia. [Methods] Biolog-ECO microplate method was used to analyze microbial community diversity in rhizosphere soil of Stipa breviflora, Artemisia frigida, Convolvulus ammannii, Heteropappus altaicus and Allium tenuissimum in the 2 plots of Adege and Gentala in Siziwang Banner. [Results] There are significant differences in the number of culturable microorganisms in the rhizosphere soil of 5 different plants in two different grasslands (P<0.05). The total number of culturable microorganisms in S. brevifolia in Adege grassland is significantly higher than that of other plants. The total number of cultivable microorganisms in the rhizosphere soil of H. altaicus in the Gentala grassland was significantly higher than that of other plants. The average color change rate (AWCD) of rhizosphere soil microbes of different plants in the two grassland showed that the AWCD of rhizosphere soil in Gegentala grassland was higher than that in Adege grassland, and showed “S” type change. After 96 hours of cultivation, the Shannon index and Simpson index of the five plants in the Gentara grassland were higher than those in the Adege grassland, and the microbial diversity index of the rhizosphere soil of C. ammannii was very different in the two grasslands. The utilization of carbon sources by soil microorganisms is mainly amino acids and carbohydrate carbon sources, and it is significantly enriched for functional microorganisms such as L-asparagine, r-hydroxybutyric acid, L-serine and D-galacturonic acid. AWCD of rhizosphere soil microorganisms and diversity index of bacteria, actinomycetes and total number of soil microorganisms have a very significant positive correlation (P<0.01). Evenness index and total number of bacteria, actinomycetes and soil microorganisms have significantly negative correlation (P<0.05). [Conclusion] different plant rhizosphere soil microorganisms had different utilization and preference of carbon source. The number of microorganisms in rhizosphere soil was higher, the microbial carbon metabolism capacity and microbial community diversity was more abundant.