Taxonomy And Phylogeny Of Endophytic Fusarium Species From Dracaena In Yunnan

The genus Fusarium belongs to the family Nectriaceae(Ascomycota,Sordariomycetes,Hypocreales.Fungi of this genus are important plant pathogens,which can cause a variety of plant diseases.Some Fusarium species can also cause diseases and infections to humans and animals,giving rise to great damage to human life and agricultural production.Fusarium is one of the most difficult fungi for researchers to identify with its richness and variety,as well as the obvious intraspecific variation and physiological differentiation.At present,more than1,600 Fusarium taxa are available(as of March 2021)in Myco Bank(http://www.Myco Bank.org)and Index Fungorum(fungorum.org).However,study on the classification of species in this genus is not perfect due to their inaccurate identification,incomplete morphological description,and the phenomenon of synonym and homonym.As a result,there are less than 400 effective names of this genus reported.Spesices of Fusarium are widely distributed in the world.The diversity and pathogenicity of Fusarium have always been the focus of research.Except for a few studies on the effect of Fusarium on the secretion of blood exhaust,there are no systematic studies on the taxonomy,phylogeny and evolution of endophytic Fusarium from Dracaena in Yunnan,as well as the construction of germplasm bank.In this study,dragon blood trees were collected from different locations in Yunnan in2019 and 2021,more than 400 Fusarium strains were isolated Species identification and classification were carried out by combining morphological characteristics with molecular phylogeny.The phylogenetic framework of Fusarium was constructed using the joint dataset of five genes(ITS,nr LSU,ef-1?,rpb1 and rpb2).Species diversity and dominant species characteristics of Fusarium were revealed based on ? diversity analysis.The main research results are as follows:(1)The phylogenetic tree of Fusarium was constructed based on the joint data set of five genes to reveal the phylogenetic relationships among species in this genus.Combined with morphological characteristics,the taxonomic statuses of Fusarium species were determined.A total of 176 Fusarium species were found in Yunnan,among which there were 70 potential new species.In this study,18 new species were described,including F.multiseptatum,F.simplicillium,F.albocitrinum,F.fusiforme,F.acremonium,F.didymium,F.uniconidium,F.purpureum,F.suboxysporium,F.reniformisporum,F.dracaena-cambodianium,F.multiformis,F.leptopurpureum,F.simengense,F.puerense,F.odorum,F.conicum,F.pruinosum.(2)According to the phylogenetic analysis,These potential new species belonged to 10 Fusarium species complexes,i.e.,F.decemcellulare species complex,F.solani species complex,F.lateritium species complex,F.redolens species complex,F.fujikuroi species complex,F.oxysporum species complex,F.tricinctum species complex,F.equiseti-incarnatum species complex,F.sambucinum species complexand F.aywerte species complex.(3)Based on the ? diversity analysis,it was found that Fusarium species diversity was high in Yunnan,and the dominant complex species phenomenon was obvious.The dominant species was the F.aywerte species complex,followed by the F.equiseti-incarnatum species complex and the F.solani species complex.The highest variety of Fusarium species was found in the F.aywerte species complex.The results showed that the species richness of Fusarium in Puer city of Yunnan province was higher than that in Kunming city.To sum up,there is a large amount of Fusarium in the body of D.draco.More new Fusarium species will be found as more Fusarium are isolated from D.draco.Dracaena draco is the natural resource bank of Fusarium.The discovery of numerous new Fusarium species is of great value to perfect the phylogenetic framework of Fusarium and enrich the new taxa of this genus.It also provides a new way to understand the relationship between Fusarium and Dracaena.