放牧对冷蒿根际土壤微生物数量和群落功能多样性的影响

发布时间：2018-06-01 07:31

本文选题：植物学 + Biolog-ECO板　；参考：《浙江农林大学学报》2017年01期

【摘要】：为揭示放牧扰动对内蒙古典型草原植物冷蒿Artemisia frigida根际土壤微生物的影响,运用平板计数法和Biolog-ECO板技术,对不同放牧强度[对照(ck),轻度放牧(LG),重度放牧(HG)]下冷蒿根际(ARS)和非根际(NRS)土壤微生物群落特征及其功能多样性进行了研究。结果表明:不同放牧强度下冷蒿根际土壤微生物数量均显著高于非根际土壤(P0.05),土壤微生物均以细菌占优势。Biolog分析显示,土壤微生物群落代谢活性(AWCD)随培养时间延长而逐渐增加,不同放牧强度处理后AWCD值差异显著(P0.05),大小顺序依次为LG-ARSck-ARSckNRSLG-NRSHG-ARSHG-NRS。土壤微生物群落Shannon指数、Simpson指数、Mc Intosh指数和丰富度指数的总体趋势为ck-ARS和LG-ARS最高,ck-NRS,LG-NRS和HG-ARS次之,HG-NRS最低。不同放牧强度的土壤微生物对不同碳源利用强度存在较大差异(P0.05),其中LG-ARS利用率最高,HG-NRS利用率最低,糖类和氨基酸类碳源是各放牧强度下土壤微生物的主要碳源。聚合物类和氨基酸类碳源在主成分分离中发挥了主要贡献作用。总之,放牧处理能够降低土壤微生物群落多样性,但冷蒿根际微生物种群密度和群落多样性均高于非根际,说明冷蒿生长能够提高土壤微生物群落功能多样性,削弱放牧干扰;冷蒿根际丰富的土壤微生物有利于改善土壤微生态,进而促进冷蒿生长,使它们成为草场退化的阻击者。
[Abstract]:In order to reveal the effect of grazing disturbance on the rhizosphere microbes of Artemisia frigida, a typical grassland plant in Inner Mongolia, the plate counting method and Biolog-ECO plate technique were used. The soil microbial community characteristics and functional diversity of Artemisia frigida Rhizosphere (ARS) and non-rhizosphere (NRSs) under different grazing intensities (control, light grazing, HG) were studied. The results showed that the number of microbes in rhizosphere soil of Artemisia frigida was significantly higher than that in non-rhizosphere soil under different grazing intensities. Biolog analysis showed that the metabolic activity of soil microbial community increased with the increase of culture time. The AWCD values of different grazing intensities were significantly different (P0.05), and the order of size was LG-ARSck-ARSckNRSLG-NRSHG-ARSHG-NRSs. The general trend of Shannon index, Mc Intosh index and richness index of soil microbial community was the highest in ck-ARS and LG-ARS in LG-NRS and the lowest in HG-ARS. Soil microbes with different grazing intensities had significant differences in the utilization intensity of different carbon sources (P0.05), among which LG-ARS utilization ratio was the highest and HG-NRS utilization rate was the lowest, and carbohydrate and amino acid carbon sources were the main carbon sources of soil microorganisms under different grazing intensities. Carbon sources of polymers and amino acids play a major role in the separation of principal components. In a word, grazing treatment could reduce the diversity of soil microbial community, but the population density and community diversity of Artemisia frigida rhizosphere were higher than that of non-rhizosphere, which indicated that the growth of Artemisia frigida could improve the functional diversity of soil microbial community and weaken grazing disturbance. The rich microbes in the rhizosphere of Artemisia frigida can improve the soil microecology and promote the growth of Artemisia frigida.
【作者单位】：浙江农林大学亚热带森林培育国家重点实验室培育基地;内蒙古大学生命科学学院;
【基金】：国家自然科学基金资助项目(31270756,31470704) 国家重点基础研究发展计划(“973”计划)项目(2014CB138805) “十二五”国家科技支撑计划项目(2011BAC07B01)
【分类号】：S812.2

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