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不同施肥方式对我国旱地农田土壤甲烷氧化影响的微生物机制尚不明确.本研究利用PCR-DGGE和实时荧光定量PCR技术,结合甲烷氧化速率和土壤性质测定,探索了长期不同施肥条件下暗棕壤的“土壤性质-甲烷氧化菌群落特征-土壤甲烷氧化速率”关系.结果表明,有机肥和无机肥配施处理显著降低了土壤甲烷氧化速率,降幅为61.2%,而单独施用有机肥或无机肥对暗棕壤甲烷氧化速率的影响不显著;与对照相比,有机肥处理土壤甲烷氧化菌多样性指数增加91.9%,有机肥和无机肥配施处理增加102.5%,而单施无机肥后土壤甲烷氧化菌多样性指数变化不明显;有机肥处理土壤的pmoA基因丰度显著增加,平均pmoA基因丰度为不施用有机肥的12.7倍;土壤甲烷氧化速率与甲烷氧化菌的群落结构和比活性呈显著正相关,相关系数分别为0.363和0.684,但与甲烷氧化菌群落丰度和多样性不相关;甲烷氧化菌的群落结构和比活性与土壤pH值、全氮和有机质含量呈显著正相关.上述结果说明,长期不同施肥可以通过改变暗棕壤的pH值、全氮和有机质含量等土壤性质,改变甲烷氧化菌群落结构和比活性,进而影响土壤甲烷氧化速率;有机肥和无机肥配施土壤甲烷氧化菌多样性和丰度大幅度增加,而甲烷氧化速率却显著降低,说明有机肥和无机肥配施土壤中只有部分微生物发挥了甲烷氧化活性,但有待进一步研究.
Microbial mechanism of different fertilization modes on the methane oxidation in dryland farmland in China is not yet clear.Using PCR-DGGE and real-time fluorescence quantitative PCR technology combined with the determination of methane oxidation rate and soil properties, the effects of long-term dark brown soil fertilization The results showed that the combination of organic and inorganic fertilizers significantly reduced the rate of methane oxidation in soil by 61.2%, while the application of organic fertilizer alone or Compared with the control, the diversity index of methanotrophs in organic manure increased by 91.9% and that of organic manure and inorganic manure increased by 102.5% compared with the control, while inorganic fertilizer The diversity index of soil methanotrophs did not change obviously; the abundance of pmoA gene in soil increased significantly with the average pmoA gene abundance being 12.7 times of that without organic fertilizer; the methane oxidation rate of soil and the community structure of methane oxidizing bacteria and The correlation coefficients were 0.363 and 0.684, respectively, but not correlated with the abundance and diversity of methanotrophs. Methane oxidation The results showed that long-term different fertilization could change the methane oxidation by changing the soil pH, total nitrogen and organic matter content of dark brown soil Bacterial community structure and specific activity, which in turn affected soil methane oxidation rate. The diversity and abundance of methanotrophs increased significantly with the combination of organic and inorganic fertilizers, while the methane oxidation rate decreased significantly, indicating that organic and inorganic fertilizers Only some of the microorganisms in the soil exert methane oxidation activity, but further study is needed.