抗生素土霉素对小麦根际土壤酶活性和微生物生物量的影响

【目的】探明四环素类抗生素土霉素在小麦根际的微生态效应。【方法】通过根箱模拟栽培法,研究了土霉素对小麦烟农21(对土霉素不敏感品种)和核优1号(对土霉素敏感品种)根际土壤脲酶、蔗糖酶、磷酸酶和过氧化氢酶4种酶活性以及微生物生物量的影响。【结果】(1)土霉素处理能够显著降低小麦核优1号根区、近根区和远根区土壤脲酶、蔗糖酶(根区除外)、磷酸酶和过氧化氢酶活性,而只显著降低了小麦烟农21根区、部分近根区和远根区相应的土壤酶活性。(2)土霉素能够显著增加小麦根际土壤微生物生物量氮的含量,且其影响作用随着距根表距离的增加呈逐渐增加的趋势,就小麦品种而言,土霉素对烟农21的影响大于核优1号。土霉素显著降低了小麦根际的微生物生物量碳的含量以及微生物生物量碳氮比,且随着距根表距离的增加,其影响作用逐渐减弱,就小麦品种而言,土霉素对烟农21根际土壤微生物生物量碳的影响小于核优1号。【结论】土霉素对小麦根际土壤酶活性和微生物生物量是有影响的,且存在基因型差异。如就土壤酶活性而言,土霉素对耐性品种的影响弱于敏感品种。

Effects of Antibiotics Oxytetracycline on Soil Enzyme Activities and Microbial Biomass in Wheat Rhizosphere

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 significandy increased microbial biomass nitrogen and its effects increased with the increase of distance from root surface.In terms of wheat cultivar, the effects on Yarmong 21 were stronger than on Heyou 1.OTC significantly decreased microbial biomass and C_(min)/N_(min) 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, theeffects of OTC on OTC-resistant wheat cultivars are weaker than those on OTC-sensitive wheat cultivars.