耕作方式和秸杆还田对纤维素降解细菌多样性的影响

发布时间：2018-01-07 12:39

本文关键词：耕作方式和秸杆还田对纤维素降解细菌多样性的影响　出处：《土壤学报》2016年04期 　论文类型：期刊论文

【摘要】：免耕和秸秆还田是培肥地力的重要措施,明确其对土壤纤维素降解细菌群落的影响对于土壤质量提升具有重要意义。选择中国科学院封丘农业生态国家试验站耕作秸秆还田(WtS)、免耕秸秆还田(WntS)、耕作秸秆不还田(Wt)和免耕秸秆不还田(Wnt)4种处理小区并采集土壤样品,用CMC-Na刚果红培养基对纤维素降解细菌计数,采用PCR-RFLP技术研究保护性耕作和秸秆还田对纤维素降解细菌群落的影响。结果表明,秸秆还田与免耕处理均不同程度提高了纤维素降解细菌数量。WtS、WntS、Wt和Wnt4个纤维素降解细菌基因文库中,OTUs数量分别为23、26、20和19个,秸秆还田加免耕处理多样性指数最高。本文获得的纤维素降解细菌共属于11个属,秸秆还田土壤中Streptomycetaceae、Flavobacterium、Sphingobium相对丰度明显多于秸秆不还田处理土壤;免耕处理土壤中Pseudomonas、Phyllobacterium、Paenibacillus、Promicromonosporaceae、Sphingobacterium相对丰度明显高于耕作处理土壤。典范对应分析显示四种处理纤维素降解细菌群落结构发生了较大变化,p H、全磷、有机碳和全钾与免耕处理呈显著正相关性,全氮、碱解氮、速效钾、速效磷和有机碳与秸秆还田处理呈显著正相关性。免耕和秸秆还田能提高土壤中纤维素降解细菌数量及多样性,改变纤维素降解细菌群落结构。
[Abstract]:No-tillage and straw returning to the field are important measures to increase fertility. It is of great significance to improve soil quality by determining its effect on soil cellulose degradation bacteria community. Select the National Experimental Station of Fengqiu Agroecology of Chinese Academy of Sciences to return straw to field WtSs). No tillage straw returned to field WNT Sn, tillage straw did not return to field Wt) and no tillage straw did not return to field WntN 4 kinds of treatment plots and collected soil samples. The cellulose-degrading bacteria were counted in CMC-Na Congo red medium. The effects of conservation tillage and straw returning on the cellulose-degrading bacteria community were studied by PCR-RFLP technique. Straw returning and no-tillage treatments increased the number of cellulose-degrading bacteria in different degree. The number of OTUs was 23 in the gene library of cellulose degrading bacteria (WtSX WntSN Wt and Wnt4), respectively. The diversity index of 20 and 19 straw returning treatments with no-tillage treatment was the highest. The cellulose degrading bacteria obtained in this paper belong to 11 genera. The relative abundance of Streptomycetaceaeus Flavobacteriumum Sphingobium in straw returning soil was significantly higher than that in soil without straw treatment. Pseudomonas spp. Phyllobacterium Paenibacillus. Promicromonosporaceae. The relative abundance of Sphingobacterium was significantly higher than that of tillage treatment soil. The canonical correspondence analysis showed that the community structure of cellulose-degrading bacteria in the four treatments had changed greatly. Organic carbon and total potassium were positively correlated with no-tillage treatment, including total nitrogen, alkali-hydrolyzed nitrogen and available potassium. There was a significant positive correlation between available phosphorus and organic carbon and straw returning treatment, which could increase the number and diversity of cellulose degrading bacteria in soil and change the community structure of cellulose degrading bacteria.
【作者单位】：南京农业大学生命科学学院/农业部农业环境微生物工程重点实验室;封丘农业生态国家试验站土壤与农业可持续发展国家重点实验室(中国科学院南京土壤研究所);
【基金】：国家重点基础研究发展计划项目(2011CB100504) 国家自然科学基金项目(41371262,41471239)资助~~
【分类号】：S345;S141.4
【正文快照】： 纤维素是一类重要的生物高聚物,占植物干重的30%~50%[1],它们随植物残体进入土壤后,为土壤微生物生长和繁殖提供丰富的碳源。不同种属的微生物产生不同的酶系[2],因而不同微生物来源的酶所催化的有机底物特异性有很大差别[3];此外,由于土壤中存在的纤维素种类繁多、结构复杂和

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