[Effect of environmental factors on the formation of several typical tetracycline resistance genes in soil].

The extensive use of veterinary tetracycline in the stock husbandry has led to the increasingly serious environmental pollution, the tetracycline resistance genes induced by which could bring more hazardous environmental risk than veterinary tetracycline. This study investigated the effects of environmental factors on the formation of several typical tetracycline resistance genes (tetA, tetC). The results showed that temperature, light and pH could have impacts on the formation of tetracycline resistance genes in soil, the amounts of the tetracycline resistance bacteria and resistance genes induced in different treatments all reached the maximum in the proper environmental condition (25 degrees C, 500 lx, pH7.

[Effects of long-term application of pig manure containing residual tetracycline on the formation of drug-resistant bacteria and resistance genes].

The effect of residual veterinary tetracycline on the formation of drug-resistant bacteria and corresponding resistance genes was investigated. During the research, the soil with long-term application of pig manure containing residual tetracycline was collected in autumn and summer respectively in the farmland around a certain pig farm in Shuyang City, Huang Huai area, north of Jiangsu province. At the same time, soils without application of pig manure in the farmland of this area were collected as the reference sample.

[Effect of submerging and wetting-redrying on Cd speciation and uptake by Sorghum hybrid Sudangrass in two paddy soils under spiked Cd].

Effect of continuous submerging and wetting-redrying on cadmium speciation and uptake by Sorghum hybrid Sudangrass in a Ferric-accumulic Stagnic Anthrosol and a Tipical Hapludult collected from the Taihu Lake region and the rolling downs of Yingtan, Jiangxi, China respectively, was studied by pot experiment with Cd spike in 2003. Compared to that under wetting-redrying treatment, the MgCl2-extracted pool of Cd in Huangnitu with spiked Cd of 5mg x kg(-1) and 10mg x kg(-1) was decreased from 21.8% and 28.