Abstract:

【Objective】 The objective of the experiment is to illustrate the microecological effects of the antibiotic oxytetracycline in wheat rhizosphere, 【Method】 Effects of oxytetracycline (OTC), a tetracycline, on microbial biomass and activities of soil enzymes such as urease, sucrase, phosphatase, hydrogen peroxidase in rhizosphere of wheat such as OTC resistant variety Yannong 21 and OTC sensitive Heyou 1, were studied in the present paper through rhizobox cultural method. 【Result】 The results showed that OTC significantly decreased activities of urease, sucrase (except for root zone), phosphatase, and hydrogen peroxidase in rhizosphere of Heyou 1, however the similar phenomena were only observed in root zone, some near root zone and far root zone of Yannong 21. OTC significantly increased microbial biomass nitrogen and its effects increased with the increase of distance from root surface. In terms of wheat cultivar, the effects on Yannong 21 were stronger than on Heyou 1. OTC significantly decreased microbial biomass and Cmin/Nmin and its effects decreased with the increase of distance from root surface. In terms of wheat cultivar, the effects on Yannong 21 were weaker than on Heyou 1. 【Conclusion】 Microbial activities biomass and soil enzyme activities in wheat rhizosphere could be significantly affected by OTC. For example, in terms of soil enzyme activities, the effects of OTC on OTC-resistant wheat cultivars are weaker than those on OTC-sensitive wheat cultivars.

Key words: antibiotics oxytetracycline, wheat, rhizosphere, soil enzymatic activites, soil microbial biomass