不同种植模式下番茄根际土壤养分和真菌多样性分析

Analysis on nutrients and fungal diversity of rhizosphere soil of tomatoes under different cropping patterns

为探究番茄与不同作物轮作后其土壤理化性质及真菌组成的差异,明确番茄土传病害发生的原因,在连种2茬番茄后设置番茄-番茄连作、茄子-番茄轮作、慈姑-番茄轮作3种处理,分析土壤养分及根际土壤真菌的多样性。结果表明,不同种植模式间的土壤养分含量明显不同。轮作降低了番茄根际土壤有机质和全氮含量,极显著提高了土壤有效磷含量、有效钾含量和缓效钾含量,提高了真菌的丰富度和多样性。子囊菌门(Ascomycota)、担子菌门(Basidiomycota)和被孢霉门(Mortierellomycota)为优势菌群,其中2种轮作模式间的真菌属组成最为相似,均含有被孢霉属(Mortierella)、木霉属(Trichoderma)等抑制土传病害发生的生防真菌。相关性分析结果显示,土壤pH值与Chao1指数呈正相关,Shannon指数和Simpson指数与土壤pH值、有机质含量、全氮含量呈负相关,与土壤有效磷含量、有效钾含量和缓效钾含量均呈正相关。综上所述,轮作能改善土壤肥力,提高土壤真菌群落多样性,维持土壤菌群结构的平衡;土壤pH值对真菌群落的组成影响较小,土壤含氮量较高,导致土壤真菌多样性降低。慈姑-番茄轮作是减缓番茄土传病害发生的有效方式之一,具有较好的应用前景。

The aim of the study was to investigate the difference of physical and chemical properties and fungus component of rhizosphere soils of tomatoes after rotation with different crops,and identify the causes of soil-borne diseases of tomatoes.Three treatments including continuous cropping tomatoes,eggplant-tomato rotated cropping and arrowhead-tomato rotated cropping were set after continuous cropping of tomatoes for two seasons.Soil nutrients and diversity of fungi in the rhizosphere soils were analyzed.The results showed that,there were obvious differences in soil nutrient contents among different cropping patterns.Compared with continuous cropping,contents of organic matter and nitrogen in tomato rhizosphere soils decreased,while contents of available phosphorus(P),available potassium(K)and slowly available K in the soils increased extremely significantly,and the richness and diversity of the soil fungi increased.Ascomycota,Basidiomycota and Mortierellomycota were the dominant phyla of all cropping patterns.The genus composition of fungi between two rotation patterns was the most similar,containing biocontrol fungi such as Mortierella and Trichoderma which could inhibit soil-borne diseases.Results of correlation analysis showed that,soil pH value was positively correlated with Chao1 index,while Shannon index and Simpson index were negatively correlated with soil pH value,organic matter content and total nitrogen content,and were positively correlated with soil available P content,available K content and slowly available K content.In conclusion,crop rotation could improve soil fertility,increase the community diversity of soil fungi and maintain the balance of soil microbial community structure.Soil pH value had little effect on fungal community composition,and nitrogen content in the soil was high,which caused reduction of fungal community diversity.Arrowhead-tomato rotation is one of the effective ways in slowing down the occurrence of soil-borne diseases of tomatoes,which has a good application prospect.