大气中臭氧浓度增加对根际和非根际土壤微生物的影响

在大田试验下,研究了冬小麦在不同的臭氧浓度下根际和非根际土壤细菌、真菌、放线菌数量的动态变化。结果表明,随着生育时期的推进,微生物数量呈现规律性的变化,其中微生物总量在抽穗期达最大。根际、非根际土壤细菌和真菌数量均随着生育期的推进呈先增大后降低的变化趋势,分别在抽穗期和孕穗期达最大。根际、非根际土壤放线菌数量随生育期呈下降的趋势,整个生育期内臭氧浓度的升高降低了土壤微生物的数量,不同的臭氧浓度处理间细菌数量差异达显著性水平,真菌数量差异只在成熟期达显著,放线菌差异不显著。

Effects of simulated elevated atomspheric O3 concentration on the quantity of microorganisms in winter wheat rhizospheric and non-rhizospheric soils

A field experiment was carried out to explore dynamics of bacteria,fungus and actinomyces in population in rhizospheric and non-rhizospheric soils of winter wheat growing under different concentrations of atmospheric ozone (100 and 150 nl L-1). Results suggest that with the succession of the growing stages, the microbes in total showed a regular curve, reaching a peak at the heading stage. In the rhizospheric and non-rhizospheric soils, bacteria and fungi displayed a saddle-shaped curve, rising first and declining later, reaching a peak at the heading and booting stages, respectively, whereas actinomyces a declining trend throughout the growing period. During the entire growth period,O3 treatment had significant effect on microbes, with bacteria dropping significantly in population under elevated O3 concentration. However, fungi varied sharply only at the mature stage and actinomyces did insignificantly at any stage.