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【目的】探究溴甲烷熏蒸对土壤反硝化作用的影响及机制。【方法】本研究采用nos Z-PCR-RFLP(Restriction fragment length polymorphism)方法、nos Z-MPN-PCR(Most-Probable-Number-PCR)计数法和土壤硝酸根的消灭率方法研究溴甲烷熏蒸对土壤nos Z型反硝化细菌群落结构、数量及反硝化活性的影响。【结果】实验结果说明溴甲烷熏蒸剂熏蒸土壤100 d土壤的反硝化作用与对照无显著差异(P>0.05)。溴甲烷熏蒸土壤和对照土样nos Z型反硝化细菌群落的Margalef指数,Shannon-Wiener和Evenness指数无显著差异(P>0.05)。溴甲烷熏蒸土壤和对照土壤中存在Uncultured bacterium partial rhodopsendomonas、pseudomonas fluorescens、Herbacspirillum、Mesorhizobium和Bradyrhizobium,并且此6种微生物均是试验土样和对照土样的优势种群;对照土壤中检测到Azospirillum、Rhizobium melibei和Nitrosospira multiformis,在溴甲烷熏蒸土壤中未检测到;而溴甲烷熏蒸土壤中检测到Uncultured Azospirillum,Mesorhizobium在对照土壤中未检测到。通过nos Z-MPN-PCR计数法得出反硝化细菌数量比对照低1.4倍。【结论】说明溴甲烷熏蒸100d土壤的nos Z型反硝化微生物群落组成和反硝化细菌数量发生变化,而土壤的反硝化作用与对照无显著差异。
【Objective】 The objective of this study was to investigate the effects of methyl bromide fumigation on soil denitrification and its mechanism. 【Method】 In this study, nos Z-PCR-RFLP (Restriction fragment length polymorphism) method, nos Z-MPN-PCR (Most-Probable-Number-PCR) counting method and soil nitrate elimination rate were used to study the effects of methyl bromide fumigation on soil Effects of nos Z Type Denitrifying Bacteria Community Structure, Quantity and Denitrification Activity. 【Result】 The results showed that the denitrification of fumigated soil with methyl bromide fumigant for 100 days was not significantly different from that of the control (P> 0.05). The Margalef index, Shannon-Wiener, and Evenness index of nosy-Z type denitrifying bacteria in methyl bromide fumigation soil and control soil sample were not significantly different (P> 0.05). Uncultured bacterium partial rhodopsendomonas, pseudomonas fluorescens, Herbacspirillum, Mesorhizobium and Bradyrhizobium were present in fumigated and fumigated soils of methyl bromide, and all six dominant microorganisms were the dominant species of test soil and control soil samples. Azospirillum, Rhizobium melibei and Nitrosospira multiformis, undetectable in methyl bromide fumigation soil; Uncultured Azospirillum was detected in methyl bromide fumigation soil, and Mesorhizobium was not detected in control soil. The number of denitrifying bacteria was 1.4 times lower than the control by the nos Z-MPN-PCR counting method. 【Conclusion】 The result shows that the composition of nos Z-type denitrifying microorganisms and the number of denitrifying bacteria change after 100 days of methyl bromide fumigation, while the denitrification of soil has no significant difference with the control.