中文摘要：

选择长江三角洲地区代表性人为耕作土壤青紫泥为研究对象，通过网室盆栽试验研究了青紫泥-水稻作物系统中汞的微生物学效应。结果表明：水稻收获后，除土壤的代谢商随汞处理浓度的增加而增加外，不同汞处理后土壤微生物量碳、呼吸强度和微生物生物商均表现为在低浓度汞处理（≤1．5mg／kg）时有促进作用，在高浓度汞处理（≥2mg／kg）时则表现出抑制作用。综合来看，土壤微生物商是汞处理后比较敏感的微生物学指标。此外，种植水稻后，随处理水平的增加，与对照相比，青紫泥各汞处理土壤微生物群落的代谢剖面AWCD值均降低；青紫泥中各处理的AWCD值均随培养时间的增加而增强，且呈“S”型指数增长模式；青紫泥中各处理的Simpson指数和McIntosh指数均比对照低，其中Simpson指数和外加汞浓度之间存在显著的相关性，可作为反映青紫泥微生物群落结构受汞污染程度的有效指标。

英文摘要：

One representative soil for rice production in China, locally referred to as a purplish clayey soil （PCS） and classified as Gleyi-Stagnie Anthrosols in FAO/UNESCO nomenclature,was respectively collected from Deqing County,Zhejiang Province. Both laboratory and greenhouse pot experiments using rice as indicator plants were conducted to investigate mercury ecological dose responses of basal respiration,microbial biomass carbon,metabolism quotient, microbial quotient, soil microbial function and community structure diversity in the PCS soil at Hg^2＋ loadings of 0,0.25,0.5,1,1.5,2,3,6 mg/kg after harvesting rice plants. The results showed that mercury （Hg^2＋） pollution in the PCS-riee system had significant effects on the microbial indices. After harvesting rice plant, except for metabolism quotient, which increased with increasing level of Hg treatments, other measured microbial indices including microbial biomass carbon, basal respiration and microbial quotient increased with the increasing level of Hg treatments at low concentrations （≤1.5 mg/kg） and decreased at high concentrations （≥2 mg/kg）,and soil microbial quotient is more sensitive to Hg contamination than the other microbial indices. The results also indicate that soil microbial functional diversities of microbial community were changed to varying extent under the stress of Hg2＋ pollution. The average well color development （AWCD）on the ECO plate reduced with increasing level of Hg. There was a nonlinearly relationship between AWCD and incubation time,and the relationship followed a growth dynamic model of microbial population （Logistic curve）. The microbial community richness and McIntosh index decreased in polluted soil than the control soil. The results suggest that the structure of microbial community has been changed under Hg^2＋ stress. Mercury pollution decreased the functional diversity of microbial community,and reduced the microbial utilization of different carbon resources.