不同栽培模式对辣椒根际连作土壤微生物区系和酶活性的影响

Effects of different cultivation patterns on soil microbial community and enzyme activity in continuous cropped pepper field

以连作3年辣椒、大蒜-辣椒轮作、玉米-辣椒间作根际土壤为研究对象,探讨了大蒜-辣椒轮作和玉米-辣椒间作处理对连作辣椒土壤微生物群落和酶活性的影响,以期为缓解辣椒连作障碍提供理论依据。结果表明,与连作3年辣椒土壤相比,轮间作处理的土壤过氧化氢酶、脲酶活性显著提高,细菌、放线菌数量显著增加,真菌数量显著减少( P< 0.05)。高通量测序结果表明,轮间作处理土壤微生物群落结构组成相似,但与连作3年土壤微生物结构差异较大,供试土壤中细菌优势种群为变形菌门(Proteobacteria)、酸杆菌门(Acidobacteria),并且酸杆菌门(Acidobacteria)、拟杆菌门(Bacteroidete)、浮霉菌门(Planctomycetes)和黄单孢菌目(Xanthomonada)在不同处理土壤中相对丰度差异显著;真菌优势种群为子囊菌门(Ascomycota)、担子菌门(Basidiomycota),其中镰刀菌属( Fusarium )、座囊菌纲(Dothideomycetes)、接合菌门(Zygomycota)在不同处理土壤中相对丰度差异显著( P< 0.05)。此外,轮间作处理能够显著降低潜在病原菌的相对丰度并提高潜在有益菌丰度,从而改善土壤微生物结构,同时显著提高了土壤酶活性和土壤细菌群落多样性。

The effects of rotation and intercropping on soil microbial community and enzyme activity were studied by taking three years of continuous cropping of pepper,garlic-pepper rotation and maize-pepper intercropping rhizosphere soil as objects,which was expected to provide theoretical basis for relieving pepper continuous cropping obstacle. Results showed that rotation and intercropping significantly enhanced the activities of catalase and urease,and increased the biomass of bacteria and actinomycetes while the biomass of fungi was greatly decreased compared with continuous cropped soil ( P< 0.05). According to high-throughput sequencing results,the soil microbial structure of rotation field was similar to intercropping soil but far different from continuous cropped soil. Findings revealed that Proteobacteria and Acidobacteria were dominant bacterial populations,while Ascomycota and Basidiomycota were leading fungi phylum among the tested soil. Moreover,the relative abundances of Acidobacteria,Bacteroidete,Planctomycetes,Xanthomonada and Fusarium,Dothideomycetes,Zygomycota among different treatments were much significant ( P< 0.05). In conclusion,rotation and intercropping enhanced soil enzyme activity and soil bacterial community diversity. Besides,they improved soil microflora by reducing the relative abundance of potential pathogens while increasing the abundance of potential beneficial bacteria.