余干辣椒连作对土壤理化性质及微生物多样性的影响

Effects of Continuous Cropping of Yugan Pepper on Soil Physicochemical Properties and Microbial Diversity

【目的】探究连作对余干辣椒产量、品质、土壤理化性质和土壤微生物多样性的影响。【方法】以余干辣椒为试材,比较连作对土壤微生物群落、土壤养分及余干辣椒的产量和品质变化,分析连作对余干辣椒土壤微生物多样性的影响。【结果】连作导致土壤真菌数量显著增加,B/F比值下降,土壤逐渐转变为真菌型土壤。连作导致余干辣椒果实纵径显著下降,降低单果重,进而降低单株产量,小区减产效应显著。连作提高了果实辣椒素、可溶性糖含量和降低了维生素C含量,但对余干辣椒品质变化不显著。基于Illumina HiSeq高通量测序分析,连作导致真菌群落的丰富度提高,多样性下降。微生物群落结构分析,连作显著提高子囊菌门的相对丰度,降低了球囊菌门、担子菌门的相对丰度,同时提高了优势真菌Fusarium、降低了优势细菌Sphingomonas、Gemmatimonas相对丰度。这可能是余干辣椒连作导致的土壤微生物群落恶变的直接原因。【结论】连作两年使余干辣椒减产严重,对品质变化的影响不显著。土壤有害菌Ascomycota、Fusarium的相对丰度提高导致连作余干辣椒土壤微生物群落变恶。

[Objective]This study aims to explore the effects of continuous cropping on yield,quality,soil physical and chemical properties and soil microbial diversity of Yugan pepper.[Method]The effects of continuous cropping on soil microbial community,soil nutrient,yield and quality of pepper were compared,and the soil microbial diversity was analyzed.[Result]The number of soil fungi increased significantly,the B/F ratio decreased,and the soil gradually changed to fungal soil.Continuous cropping resulted in a significant decrease in fruit diameter,fruit weight and yield per plant,as well as a significant yield reduction effect in plots.Continuous cropping increased the content of capsaicin and soluble sugar,while it decreased the content of vitamin C.Illumina HiSeq high-throughput sequencing results were analyzed,continuous cropping increased the richness and decreased the diversity of fungal communities.Analysis of microbial community structure showed that continuous cropping significantly increased the relative abundance of Ascomycota,decreased the relative abundance of Glomeromycota and Basidiomycota,and increased the relative abundance of dominant fungi Fusarium and decreased the relative abundance of dominant bacteria Sphingomonas and Gemmatimonas.This may explain soil microbial community deterioration caused by continuous cropping of Yugan pepper.[Conclusion]In summary,continuous cropping for two years reduced the yield of Yugan pepper seriously and had no significant effect on the quality change.The relative abundance of soil harmful bacteria Ascomycota and Fusarium increased,leading to the deterioration of soil microbial community of continuous cropping Yugan pepper.