Diversity Analysis Of Culturable Fungal Community In The Rhizosphere Soil Of P. Chinensis At Different Fruiting Stages

In order to understand the composition and diversity of cultivable fungi community in the rhizosphere soil of Cinnamomum migao fruit at different stages of fruit development(Young fruit stage,Swelling stage and Mature stage),this study used the rhizosphere of Cinnamomum migao at different stages of fruit development in a year.The soil is the research object.The Rhizosphere fungus of Cinnamomum migao is separated and purified by the dilution plate method.The fungi species are identified through morphological and molecular biological methods,and the structure of the fungal community at different stages of fruit development is analyzed.At the same time,8soil physical and chemical indicators and 5 soil are determined.Enzyme activity indicators and the composition of root exudates were identified by GC-MS analysis,and the correlation between dominant fungal groups and soil physical and chemical factors,enzyme activities and root exudates in each period was explored,in order to reveal the fungi that can be cultivated in the rhizosphere during the development of Cinnamomum migao fruits The dynamic change law of the composition and the change law of the soil environment provide certain theoretical support for the evaluation of the changes in the rhizosphere soil environment during the growth and development of the fruit,and at the same time deepen the understanding of the diversity of cultivable fungi in the rhizosphere soil of Cinnamomum migao at different fruit stages,To lay the foundation for the development of special functional strains of the seedling medicine Cinnamomum migao,and the establishment of a fungus strain bank for the rhizosphere soil.The main findings are as follows:(1)A total of 529 fungi were isolated from the rhizosphere soil during the three stages of fruit development.They were initially identified as 108 species in 57 genera.The number of fungi isolated was in the order of Swelling stage ? Young fruit stage ? Mature stage.Among the fungi isolated in 3 stages,8 genera are shared by 3 stages,namely Nectria,Pleosporales,Fusarium,Penicillium,Trichoderma,and Clonostachys,Aspergillus and Purpureocillium.(2)The fungi isolated and identified in the Young fruit stage belonged to 31 genera and 53 species,the Swelling stage belonged to 36 genera and 64 species,and the Mature stage belonged to 16 genera and 31 species.Jaccard similarity analysis showed that the rhizosphere fungal community composition was moderately dissimilar during the three fruiting periods,and the community distribution was significantly different.Shannon's diversity index,Simpson dominance index,Margalef richness index and Pielou evenness index change with fruit period are all shown as: Swelling stage?Young fruit stage?Mature stage.There are obvious differences in the number of cultivable fungi,community diversity and composition in the rhizosphere soil of Cinnamomum migao fruits at different stages of development.(3)During the development of Cinnamomum migao fruit,the p H of rhizosphere soil fluctuates slightly.The p H range of NQ and XL is between 6.00 and 7.00,which is a neutral soil,while the p H range of BP is between 5.00 and 6.00;the content of OM fluctuates greatly,showing a trend of first increasing and then decreasing;the content of TN and AN in the soil shows a gradual decrease trend as a whole;The content of TP and TK showed an increase first and then a decrease,and the content of AP decreased rapidly during the mature period.Rhizosphere S-UE and S-ACP activities as a whole show that Young fruit stage?Mature stage?Swelling stage;NQ,BP rhizosphere S-CAT activity show that Mature stage?Young fruit stage?Swelling stage,while XL shows Young fruit stage ? Mature stage ? Swelling stage;the activity of NQ and XL rhizosphere S-CL generally shows that Swelling stage ? Mature stage ? Young fruit stage,BP showed that Young fruit stage ? Mature stage ? Swelling stage;NQ rhizosphere S-SC activity showed Young fruit stage?Mature stage?Swelling stage as a whole,and BP showed Swelling stage ? Young fruit stage>Mature stage,XL performance is Young fruit stage>Swelling stage>Mature stage.(4)GC-MS was used to analyze the root exudates samples of Cinnamomum migao after methanol extraction.The results showed that the peak number at the Young fruit stage was BP?NQ?XL.There were 33 types of NQ,35 types of BP,XL There are 10 types.The number of peaks in the Swelling period is BP?NQ?XL,there are 29 types of NQ,37 types of BP,and 20 types of XL.The number of peaks in the Mature period is NQ?BP?XL.There are 24 types of NQ,29 types of BP,and 8 types of XL.(5)The diversity of the cultivable fungal community structure in the rhizosphere soil of Cinnamomum migao at different fruiting stages has a certain correlation with soil physical and chemical factors,enzyme activities and root exudates.In the Young fruit stage,OM plays a decisive role in the change of the rhizosphere cultivable fungal community composition.Clonostachys,Penicillium,Beauveria,Fusarium,Metarhizium There is a positive correlation with the content of TN,AN,TP,AP,TK,and AK;Penicillium,Trichoderma and S-CAT activity is positively correlated,Saksenaea is positively correlated with S-CL;Purpureocillium is positively correlated with.gamma.-Sitosterol is positively correlated.During the Swelling period,Schizophyllum,Gongronella,Saksenaea,Talaromyces and AN,AK content are positively correlated to varying degrees,Metarhizium is positively correlated with OM;S-CL plays a decisive role in the change of rhizosphere cultivable fungal community composition.Fusarium and Metarhizium are positively correlated with S-CL;Cedrol plays a decisive role in the change of rhizosphere culturable fungal community composition.Metarhizium and Cedrol are positively correlated with relative content,and Trichoderma is negatively correlated with various exudates.At the Maturity stage,the genus Purpureocillium and Penicillium are positively correlated with TP,TN,AP,and AK in varying degrees;S-CAT plays a decisive role in the change of rhizosphere cultivable fungal community composition.Penicillium and Purpureocillium are negatively correlated with S-CAT and S-CL;Aspergillus,Clonostachys fungi group and Hexadecanoic acid,methyl ester,n-Hexadecanoic acid,.beta.-Sitosterol,Cedrol showed positive correlation to varying degrees.