三种不同利用方式土壤上黄瓜根际微生物群落差异

蔬菜塑料大棚是一种高度集约化利用的设施农业类型,在太湖地区一般由原来的稻麦(或油菜)轮作或露地蔬菜改变而来。稻麦(或油菜)轮作或露地蔬菜改为蔬菜塑料大棚后,土壤养分高度累积,出现了次生盐渍化和酸化的现象1-2]。可能受土壤酸化和次生盐渍化的影响,蔬菜塑料大棚土壤

Differences in microbial community in cucumber rhizosphere soil between three fields under different land use

When the traditional rice wheat (or rape) rotation land or the open field vegetable land had been turned into the polytunnel greenhouse vegetable land since 1995, the soil microbial diversity was decreased whilst soil borne fungal disease was badly increased. In our study, the growth media for pot experiment were soils from the three land use types as described above. Half of cucumber seedlings from the three soils of different land use types were inoculated with Fusarium oxysporum f. sp. Cucumerinum. By examining the microbial populations in rhizosphere soils through greenhouse cucumber pot experiment, the aim of this study was to investigate the effects of land use types and inoculation of Fusarium oxysporum f. sp. Cucumerinum on soil microflora, plant growth promoting rhizobacteria and Fusarium oxysporum, and to relate these examinations to the suppressiveness of cucumber Fusarium wilt. The results show that land use types and inoculation of Fusarium oxysporum f. sp. Cucumerinum had significant effects on these parameters. The population ratio of bacteria to fungi were significant decreased in the polytunnel greenhouse vegetable soil sources, compared with those in the traditional rice wheat (or rape) rotation soil sources or the open field vegetable soil sources. Pseudomonas spp. and mycorrizal infection in cucumber were significantly decreased whilst F. oxysporum populations significant increased in the polytunnel greenhouse vegetable soil sources. Stepwise multiple regression analysis showed that mycorrizal infection and Pseudomonas spp. were significantly positively correlated with cucumber biomass. A decrease of plant growth promoting rhizobacteria whilst an increase of Fusarium oxysporum in the polytunnel greenhouse vegetable soil sources may be one of main reasons for slow growth, low fruit yields and frequent Fusarium wilt.