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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 a significant protective effect on soil microorganisms, but its effects on soil photosynthetic bacteria and methanotrophs are seldom reported. In this study, the soil macrogenome 16S rDNA denaturing gradient gel electrophoresis (DGGE) and fluorescence quantitative PCR were used to compare the effects of different tillage patterns (no-tillage and conventional tillage) and different straw mulching (0,50%, 100% Effects of photosynthetic bacteria and type Ⅱ methanotrophs on the population and community structure. The results showed that the diversity of photosynthetic bacteria in no-tillage soil (diversity index H = 2.47) was significantly higher than that of conventional tillage soil (diversity index H = 2.35), and positively correlated with soil total nitrogen, slightly lower than Although the amount and diversity of photosynthetic bacteria increased with the increase of straw mulch, it was not significant. Although no-tillage and straw mulch had a beneficial effect on the quantity and diversity of type-Ⅱ methanotrophs However, the effects of tillage patterns, straw mulching and interaction between the two treatments were not significant. The population structure of photosynthetic bacteria and type Ⅱ methanotrophs did not change significantly under different treatments. The dominant populations of photosynthetic bacteria were Rhizobiales and sheaths Sphingomonadales, and the predominant species of methanotrophs of the type Ⅱ are the bacterial groups of Methyloc ystaceae.