含镉和环丙沙星有机肥对生菜中抗性基因及微生物群落的影响

发布时间：2018-03-23 09:28

本文选题：环丙沙星　切入点：镉　出处：《西北农林科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着现代畜禽养殖产业不断扩张,饲料需求量逐年增加,添加于饲料中的抗生素、重金属含量也随之上升,大量重金属、抗生素会随畜禽粪便排出体外。畜禽粪便作为有机肥施入土壤,其中所含的抗生素和重金属会对土壤生态环境、作物品质等产生一定影响。因此本试验选取人畜共用的一种喹诺酮类抗生素环丙沙星(CIP)及重金属镉(Cd),通过盆栽试验,研究了施用含镉和不同浓度环丙沙星有机肥对生菜产量与品质、抗生素抗性基因(ARGs)、土壤微生物群落结构及生菜叶片内生菌的影响。结论如下:(1)施用含Cd和CIP有机肥不同程度的提高了生菜产量。5 mg·kg-1CIP增加叶片产量、叶绿素和维生素C含量,80 mg·kg-1表现出一定的抑制作用。Cd和5 mg·kg-1CIP复合对生菜产量的促进作用最大。高浓度CIP促进生菜根部对Cd的吸收,降低叶片中Cd的累积量。(2)施用含Cd和CIP有机肥不同程度的提高了土壤中ARGs相对丰度,显著增加了叶片中int1的丰度。土壤中ARGs随CIP浓度增大而增大,Cd和CIP复合处理中qnrA、qnr S、qnrD、int1和int2的增加幅度更大。叶片内4种ARGs相对丰度随CIP浓度增大而增大。(3)施用含Cd和CIP有机肥在一定程度上影响了土壤微生物群落结构及生菜叶片内生菌。含CIP有机肥增加了土壤中微生物群落多样性,降低了丰富度,抑制了叶片内生菌多样性和丰富度。Cd和5 mg·kg-1CIP复合污染抑制作用了土壤微生物和叶片内生菌多样性和丰富度。Fluviicola、Candidatus Nitrososphaera和Kaistobacter等菌属丰度随着CIP浓度的增加而增加。Cd和CIP有机肥诱导了生菜叶片中Streptococcus、Prevotella、[Prevotella]和Neisseria丰度增加,Treponema、Fusobacterium和Leptotrichia等菌属的丰度均随CIP浓度增大而增大。施用含有Cd和CIP的有机肥会增加叶片中Streptococcus、Prevotella和Porphyromonas等潜在致病菌属的丰度,这些致病菌属可能沿食物链传递到人体,威胁人类健康。综上所述,施用含Cd和CIP有机肥后,80 mg·kg-1CIP对生菜产量有一定的抑制作用;Cd和CIP增加土壤和生菜叶片中ARGs丰度;含Cd和CIP有机肥一定程度上影响了土壤及生菜叶片内生菌微生物群落的多样性和丰富度,诱导耐药菌属和致病菌属的增加。
[Abstract]:With the continuous expansion of the modern livestock and poultry breeding industry, the demand for feed increases year by year. The content of heavy metals also increases when antibiotics are added to the feed, and a large number of heavy metals are added to the feed. Antibiotics are excreted into the soil as organic manure, which contains antibiotics and heavy metals that affect the ecological environment of the soil. Therefore, a quinolone antibiotic ciprofloxacin (CIPP) and the heavy metal cadmium (CD) were used in this experiment. The effects of cadmium and ciprofloxacin organic fertilizer on the yield and quality of lettuce were studied. The effects of antibiotic resistance gene (ARGsN), soil microbial community structure and endophytic bacteria on vegetable leaf slices. Conclusion: application of organic fertilizer containing CD and CIP increased the yield of lettuce by 5. 5 mg kg-1CIP in varying degrees. Chlorophyll and vitamin C content of 80 mg kg-1 showed a certain inhibitory effect. CD and 5 mg kg-1CIP could promote the yield of lettuce. High concentration of CIP could promote CD absorption in the root of lettuce. Application of organic fertilizer containing CD and CIP increased the relative abundance of ARGs in soil. ARGs in soil increased with the increase of CIP concentration, and the increase of QnrAQNR SchiqnrDnt1 and int2 in mixed treatments with the increase of CIP concentration was more significant. The relative abundance of four ARGs in leaves increased with the increase of CIP concentration, and the relative abundance of four kinds of ARGs increased with the increase of CIP concentration. To some extent, the soil microbial community structure and endophytic bacteria in vegetable leaf were affected by organic fertilizer and CIP. Organic fertilizer containing CIP increased the diversity of microbial community in soil. Reduced richness, The diversity and richness of endophytic bacteria in leaves were inhibited by inhibiting the compound pollution of endophytic bacteria. CD and 5 mg kg-1CIP. The diversity and abundance of endophytic bacteria in soil and leaf slices. Fluviicolaena Candidatus Nitrososphaera and Kaistobacter increased with the increase of CIP concentration. CD and CIP increased with the increase of CIP concentration. The abundance of Streptococcus prevotella, [Prevotella] and Neisseria increased with the increase of CIP concentration, and the application of organic fertilizer containing CD and CIP increased the abundance of Streptococcus prevotella and Porphyromonas in leaves. These pathogenic bacteria may be transmitted to human body along the food chain and threaten human health. In conclusion, the application of 80 mg kg-1CIP containing CD and CIP can inhibit the yield of lettuce to some extent. CD and CIP can increase ARGs abundance in soil and vegetable leaf. CD and CIP organic fertilizer affected the diversity and richness of endophytic microorganism community in soil and vegetable leaf to some extent, and induced the increase of resistant and pathogenic bacteria.
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S141;S636.2

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