2种杀菌剂对茉莉根际土壤酶活性和微生物碳源代谢多样性的影响

Effects of Two Fungicides on Rhizosphere Soil Enzyme Activity and Microbial Carbon Source Metabolic Diversity of Jasminum sambac

本研究在人工温室大棚条件下,以白绢病染病茉莉植株根际土壤为材料,分析比较2种杀菌剂(氟啶胺和戊唑醇)处理对土壤理化性质、土壤酶活性及土壤微生物群落碳源代谢多样性的影响。结果表明:在2种不同浓度杀菌剂处理前后,茉莉根际土壤理化性质各项指标具有显著差异。50%氟啶胺处理后,土壤pH和有机质含量分别降低14.8%和18.8%,而50%戊唑醇处理后,有机质含量则显著增加,增幅高达76.8%;50%戊唑醇对土壤全氮、有效磷、速效钾的影响最为显著,其中,全氮最高增幅为77.8%;有效磷最高增加了1.3倍;速效钾最高增幅达2.1倍。杀菌剂对茉莉根际土壤蔗糖酶、脲酶、酸性磷酸酶活性具有显著影响。50%氟啶胺处理后,蔗糖酶活性显著降低92.8%;50%戊唑醇处理后,脲酶活性显著降低,较喷施前减少41.9%;杀菌剂处理后酸性磷酸酶活性均呈递增的变化趋势。比较2种杀菌剂处理后土壤微生物群落的碳源代谢多样性发现,CK的平均每孔颜色变化率(AWCD)最低,2种杀菌剂处理后,AWCD均降低,且戊唑醇对AWCD的抑制作用最显著。总体上,杀菌剂处理后,土壤微生物Shannon-Wiener多样性指数(H)与McIntosh均匀度指数(U)均呈下降趋势,各处理间的Simpson优势度指数(D)无显著差异;土壤微生物群落对6类碳源的代谢能力具有一定的抑制作用。土壤微生物群落碳源利用能力的主成分分析表明,氨基酸类和碳水化合物2类碳源的利用率相似,多聚物类和羧酸类相似。本研究结果可为评估杀菌剂处理后茉莉根际土壤微生物的生态功能提供科学依据。

In this study,the rhizosphere soil of jasmine was used as the material under the condition of artificial green-house to analyze and compare the effects of two fungicides(fluazinam and tebuconazole)on soil physical and chemical properties,soil enzyme activities in addition to carbon source metabolic diversity of soil microbial community.The indexes of soil physical and chemical properties were different under the application of the two fungicides of different concentration.The pH value and organic matter content of soil decreased by 14.8%and 18.8%,respectively,after application of 50% fluazinam. The content of organic matter increased by 76.8% after treatment with 50% tebuconazole. 50% of tebuconazole had the most significant effect on total nitrogen, available phosphorus and available potassium, and the highest increase of total nitrogen was 77.8%. The maximum available phosphorus increased by 1.3 times while the content of available potassium increased by 2.1 times. The effects of fungicides on the activities of sucrase, urease and acid phosphatase in jasmine rhizosphere soil were significant. The sucrase activity was significantly decreased by 92.8% after treated with 50% fluazinam. The urease activity decreased significantly after spraying 50% tebuconazole, which was 41.9% lower than that before spraying. At the same time, the acid phosphatase activity showed increasing trends after treated with fungicides. To compare the carbon source metabolic diversity of soil microbial community after application of the fungicides found that the value of average well color development (AWCD) in CK was the lowest. After the treatment of the two fungicides, AWCD decreased compared with that before spraying, among which the in-hibitory effect of tebuconazole on AWCD was the most significant. In general, the Shannon diversity index (H) and evenness index (U) of soil microorganisms showed a decreasing trend with fungicide treatment. However, there was no significant difference in the dominance index (D) among all treatments. Soil microbial community had a certain inhibi-tory effect on the metabolic diversity of six kinds of carbon sources after fungicides application. In addition, principal component analysis of soil microbial community carbon source metabolic diversity revealed that amino acids and carbohydrates had similar utilization rates. In addition, polymers and carboxylic acids were similar. This study analyzed and compared the effects of fluazinam and tebuconazole on the microbial characteristics and carbon source metabolic diversity in jasmine rhizosphere soil, and the results would provide a scientific basis for evaluating the ecological func-tion in rhizosphere soil microorganisms of jasmines under the influence of two fungicides.