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  

Effect on functional diversity of Artemisia frigida rhizosphere soil microbial community with grazing

作　　者：臧晓琳[1] 张洪芹[1] 王鑫朝 马元丹[1] 宝音陶格涛[2] 高岩[1] 张汝民[1] 

机构地区：[1]浙江农林大学亚热带森林培育国家重点实验室培育基地,浙江临安311300 [2]内蒙古大学生命科学学院,内蒙古呼和浩特010021

出　　处：《浙江农林大学学报》2017年第1期86-95,共10页Journal of Zhejiang A&F University

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)

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(P<0.05),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(P<0.05),大小顺序依次为LG-ARS>ck-ARS>ckNRS>LG-NRS>HG-ARS>HG-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(P<0.05),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。To understand the response mechanism of soil microbial biomass in the rhizosphere soil of Artemisia frigida, we measured the functional diversity of Artemisia frigida rhizosphere （ARS） and non-rhizosphere soil （NRS） microbial community under three levels （no, light and heavy） of manipulative grazing conditions using the Biolog EcoPlate analysis. Results showed that with different grazing intensities, the soil microbial population of ARS was significantly greater than NRS （P 〈 0.05） with bacteria playing a dominant role in all soil micro-bial species accounting for 88%-97%. The average well color development （AWCD）, directly reflecting micro-bial activity and functional diversity, increased over time; whereas, AWCD for the two soil types significantly changed （P 〈 0.05） along with increased grazing intensity such that： LG-ARS 〉 ck-ARS 〉 ck-NRS 〉 LG-NRS 〉 HG-ARS 〉 HG- NRS. The Simpson, Shannon-Wiener, richness, and McIntosh indexes of ck-ARS were all higher （P 〈0.05 ）than HG-NRS, and for ARS, population density and diversity of microbial communities were higher （P 〈 0.05） than NRS. The PCA was used to obtain two principal components related to soil mi-crobial biomass utilization and that explained separately 52.1% （PC1） and 17.2% （PC2）. The carbon car-boxylic and amino acid play a major role in the separation of principal components. Thus, frigida growthcould increase diversity of the soil microbial community, weaken grazing disturbances, improve the soil micro-ecology, and prevent degradation of the grasslands. [Ch, 3 fig. 3 tab. 39 ref.]

关 键 词：植物学 Biolog-ECO板 微生物功能多样性 放牧 冷蒿 土壤微生物 

分 类 号：S718.5[农业科学—林学] S154.3