| Yeasts are single-celled fungi that are widely distributed throughout the natural world.At present,more than 1,500 yeasts are known.In recent years,scholars at abroad have studied the diversity of yeasts in a variety of habitats.Among them,extreme environments,soils,and freshwater habitats have been studied.The study of yeasts in orchard soils involves vineyards,apple orchards,and the diversity of yeasts in Taoyuan.Sex research lacks systematic reports.In this study,the rhizosphere and non-rhizosphere soils and tissues of different tree ages in Taoyuan were used as raw materials.Through yeast cultivable and non-cultivable identification methods,the diversity of yeasts at different ages and the collection of yeast strains and the screening of functional yeasts were studied.The main contents of this study are as follows:1.High-throughput sequencing technology was used to analyze the relationship between rhizosphere and non-rhizosphere soils of different tree ages and the diversity of yeast community at different ages in relation to soil physical and chemical factors.2.The research methods of traditional taxonomy and molecular taxonomy discuss the diversity and dominant population distribution of yeasts of different ages in Taoyuan soil.3.Selenium-enriched yeasts,protease-producing yeasts and biocontrol yeasts were screened on the basis of isolation and identification of strains.And the initial construction of some yeast electronic files for identification.The main results are as follows:(1)The results of high-throughput sequencing indicated that the dominant rhizosphere yeast in the three-year-old soil was Rhodotorula,Hyphopichia,and Saturnispora,and the non-rhizosphere soil was Pichia.Clavispora and Meyerozyma.8 years old rhizosphere soil dominant yeast species Pichia,Cladosporium and Filobasidium,non-rhizosphere soil Cryptococcus,Trigonopsis,Papiliotrema And Cyniclomyces.The 15th-year-old rhizospheric soil had three dominant yeast species: Trigonopsis,Trichosporon,Moraxia,Meyerozyma,and Cyberlindnera.The non-rhizosphere soils were Saturnispora and Candida.Rhodotorula,and Yamadazyma.The diversity of yeasts of different ages was significantly related to some physicochemical factors,and was often negatively correlated with pH and positively correlated with organic matter,total phosphorus,and total nitrogen.(2)129 yeast strains were isolated by a culturing yeast isolation method and were identified as belonging to 12 genera and 17 species.Of the isolated yeast strains,Ascomycete yeast was the dominant group,accounting for 88% of the isolates.15 species distributed in 11 genera including Wickerhamomyces,Vanrija,Barnettozyma and Torulaspora.Basidiomycetes only account for 12% of isolates and are distributed in two species of the genus Cryptococcus.Among them,the dominant species is Wickerhamomyces,including two species,anomalus and pijperi,accounting for 33% of the total.The dominant species is Wickerhamomyces anomalu,which accounts for 17% of the total isolates.(3)42 functional yeast strains were selected.Among them,21 selenium-enriched yeasts belong to Galactomyces candidum,Galactomyces pseudocandidum,Galactomyces geotrichum,Cryptococcus albidus,Candida tropicalis,Wickerhamomyces pijperi and Vanrija albida.There were 14 lipase-producing yeasts belonging to Cryptococcus albidus,Rhodosporidium diobovatum and Barnettozyma californica.7 strains of yeast strains with antagonistic Verticillium dahliae were screened and belong to Wickerhamomyces anomalus,Barnettozyma californica,Kazachstania hellenica and Metschnikowia pulcherrima. |
