生长年限对西洋参根际土真菌群落结构的影响及多样性分析

Diversity analysis and characteristic of fungal community in rhizosphere soil of Panax quinquefolium L.in different cropping years

目的:研究生长年限对西洋参根际土真菌群落结构特征及其多样性的影响,为阐释西洋参连作障碍的形成提供理论依据。方法:分别采集未种植西洋参以及生长1、2、3、4年的根际土,利用高通量测序技术,对不同生长年限西洋参根际土壤真菌群落结构及多样性进行分析,采用FUNGuild分析真菌群落功能。结果:随着生长年限的增加,根际土真菌群落种类及多样性发生变化。在门分类水平上囊菌门(Ascomycota)、被孢菌门(Mortierellomycota)、担子菌门(Basidiomycota)、未分类真菌门(Unclassified_K_Fungi)和罗兹菌门(Rozallmycota)为优势菌群;在属分类水平上优势菌群相差较大,1年生根际土及空白土壤中占比例最大的为孢霉菌属(Mortierella),分别为51.63%和40.23%;4年生根际土中占比最大的为Pseudaleuria,为32.07%;3年生根际土中Tausonia占比最大,为25.25%;2年生根际土中短梗蠕孢属(Trichocladium)占比最大,为27.71%。西洋参根际土中真菌以腐生型为主,随着生长年限的增加,土壤病原菌型呈连续渐次性变化。结论:西洋参1年生根际土及空白土壤在不同属分类水平上群落结构具有较高的相似性,4年生根际土中的土壤真菌多样性降低,以期为西洋参种植、揭示连作障碍形成提供理论基础。

Objective:In order to provide theoretical basis for the explanation of the formation of continuous cropping obstacles in Panax quinquefolium L.,and the structure characteristics and diversity of fungal community in rhizosphere soil of Panax quinquefolium L.with different planting year.Methods:Based on the Miseq platform of Illumina,five kinds of soil samples were collected,the soil of non-plant(CK),cultivating for one year(A),cultivating for two years(B),cultivating for three years(C),cultivating for four years(D),respectively.The fungal community structure and diversity of rhizosphere soil of Panax quinquefolium L.with different planting years were analyzed by high-density sequencing technology.FUNGuild was used to analyze the functions of fungal communities.Results:With the increase of planting years,the species and diversity of rhizosphere soil fungal community showed a downward trend.At the classification level of mycota,the dominant bacteria were Ascomycota,Mortierellomycota,Basidiomycota,Unclassified_K_fungi and Rozallmycota.At the level of genus classification,there was a big difference in the dominant genera strains.Mortierella accounted for the largest proportion in A and CK,which were 51.63% and 40.23%,respectively.The largest proportion of D was Pseudaleuria,which was 32.07%.Tausonia accounted for 25.25% of C;Trichocladium was the largest genus in B,accounting for 27.71%.The fungi in the rhizosphere of Panax quinquefolium L.were mainly saprophytic,and the types of soil pathogens showed continuous and gradual changes with the increase of planting years.Conclusion:The community structure of rhizosphere soil A and CK of Panax quinquefolium L.has high similarity at different genera classification levels,while soil fungal diversity of D decreased.The difference of rhizosphere fungal community structure and diversity in different planting years increase year by year,which is expected to provide a theoretical basis for the cultivation of Panax quinquefolius L.and revealing the formation of continuous cropping obstacles.