酸性黄壤铅污染下植物根际微生物和酶活性研究

Effect of Rhizosphere on Microorganism and Enzyme Activity in Polluted Acid Yellow Soil with Lead

采用盆栽试验研究了酸性黄壤铅污染下4种草本植物根际土壤微生物数量和酶活性的变化。结果表明:植物根际土壤中细菌、真菌和放线菌对铅污染的响应因植物根系环境的不同而有所区别:4种植物根际土壤中细菌和真菌数量增加,但增幅不一致。黑麦草和早熟禾根际土壤放线菌数量降低,翦股颖根际土壤放线菌数量呈现波动起伏。4种植物根际土壤中过氧化氢酶活性、淀粉酶活性和中性磷酸酶活性与土壤铅含量都表现出负相关性,与淀粉酶活性负相关达到极显著,铅对黑麦草和狗牙根根际土壤脲酶活性表现出低浓度下激活高浓度下抑制,早熟禾和翦股颖根际土壤脲酶活性与土壤铅含量表现出正相关性。

Rhizosphere was a special area around plant roots. In order to investigate the influence of plant roots and rhizosphere microorganisms on bioremediation of soils contaminated with lead, the effect of rhizosphere on microbial numbers and activities of enzyme in rhizosphere soil were studied with rhizobag technique. The results showed that add 100-3 000 mgPb/kg to the soil, the trend of the amount of microorgnism increased. The quantity of bacterium and fungi increased, the quantity of actinomyces reduced. In the rhizosphere of four plants, the activities of catalase, neutral phosphatase, amylase and the content of lead in soil expressed negative correlation,and the negative correlation between the activity of amylase and the content of lead in soil was remarkable. In the rhizosphere of Loliurn perenne and Cynodon dactylon, the activity of urease was activated at low density of lead and descended at high density, but in the rhizosphere of Agrostis stolonifera and Poa annua, there was a positive correlation between the activity of urease and the content of lead in soil.