保护性耕作对土壤光合细菌和Ⅱ型甲烷氧化菌的影响  

Effects of conservation tillage on soil photosynthetic bacteria and type II methanotrophs

作　　者：王敬敬[1,2] 李新宇[1] 徐明恺[1] 苏振成[1] 李旭[1] 孙健[1] 张惠文[1] 

机构地区：[1]中国科学院沈阳应用生态研究所森林与土壤生态国家重点实验室,沈阳110016 [2]中国科学院研究生院,北京100049

出　　处：《生态学杂志》2012年第9期2289-2298,共10页Chinese Journal of Ecology

基　　金：国家高技术研究发展计划项目(2012AA101403)资助

摘　　要：保护性耕作对土壤微生物具有明显的保护效应,但是其对土壤光合细菌和甲烷氧化菌的影响却鲜有报道。本文采用土壤宏基因组16SrDNA变性梯度凝胶电泳(DGGE)和荧光定量PCR技术比较了不同耕作模式(免耕和传统翻耕)和不同秸秆覆盖量(0、50%、100%)对潮土中光合细菌和Ⅱ型甲烷氧化菌数量和群落结构的影响。结果表明:免耕土壤中光合细菌的多样性(多样性指数H=2.47)显著高于传统翻耕土壤(多样性指数H=2.35),且与土壤总氮呈显著正相关,数量略低于传统翻耕土壤;光合细菌的数量和多样性虽均随着秸秆覆盖量的增加而有所增加,但不显著;虽然免耕和秸秆覆盖对Ⅱ型甲烷氧化菌数量和多样性产生了有益的影响,但是耕作模式、秸秆覆盖及二者互作对其影响均不显著;不同处理中光合细菌和Ⅱ型甲烷氧化菌的种群结构无明显变化,光合细菌优势种群以根瘤菌目(Rhizobiales)和鞘脂单胞菌目(Sphingomonadales)为主,Ⅱ型甲烷氧化菌优势种群主要为甲基孢囊菌科(Methyloc ystaceae)的细菌类群。Conservation tillage has beneficial effects on soil microbes, but the effects on soil photosynthetic bacteria and methanotrophs are rarely reported. In this study, denaturing gel gradient electrophoresis （DGGE） and quantitative PCR technique were adopted to investigate the abundance and community structure of photosynthetic bacteria and type Ⅱ methanotrophs in a fluvoaquic soil as affected by different tillage modes （no-tillage and conventional tillage） and straw mulching （0, 50%, 100%）. Under no tillage, the diversity of soil photosynthetic bacteria was significantly higher but the abundance was slightly lower, as compared with those under conventional tillage, and there was a significant positive correlation between the diversity of soil photosynthetic bacteria and the soil total nitrogen. Both the abundance and the diversity of soil photosynthetic bacteria had a trend of increased with increasing amount of straw mulch. Tillage, straw mulching, and their interaction also had definite beneficial effects on the abundance and diversity of type Ⅱ methanotrophs. In all treatments, the community structure of soil photosynthetic bacteria and type Ⅱ methanotrophs had less change. The dominant groups of soil photosynthetic bacteria were Rhizobiales and Sphingomonadales, and that of type Ⅱ methanotrophs was Methylocystaceae.

关 键 词：免耕 传统翻耕 秸秆覆盖 DGGE 荧光定量PCR 

分 类 号：S154.3[农业科学—土壤学]