The Rhizosphere Soil Of Phragmites Australis Cultured Fungal Diversity And Screening Of Antagonistic Bacteria Against Pathogen

In this paper,rhizosphere soil fungis were isolated and identified by using dilution-plate method,morphological analysis and molecular biology identification method.At the same time,this article has analyzed the effect of season on fungi,carried on the salt resistance of rhizosphere soil culturable fungi of Phragmites australis and screen of antagonistic to four kinds of common plant pathogenic bacteria.The results show that in spring,summer,autumn and winter,the number of fungal colonies involved in the rhizosphere soil is 5243,5003,6388 and 4970 respectively,which belong to 9 genera 21 species,8 genera 18 species,11 genera 22 species and 6 genera 21 species respectively,in total there were 54 genera and 15 species of fungi isolated.The dominant genera are Aspergillus,Penicillium,Paecilomyces,Trichoderma,and Alternaria.The Shannon diversity index and richness index of rhizosphere fungi from different seasons were ranked as autumn > spring > summer >winter,while the evenness index was spring>summer>winter>autumn,it can be seen that the diversity and richness index showed the highest performance in autumn,but the numerical value fluctuated greatly,and the evenness index showed a little difference.Phragmites australis fungi resources are abundant in rhizosphere soil,Among them,Chrysosporium,Corticium,Gliocladium,Talaromyces and Rhizopus are the genera which can not be found in the non-vegetation soil;The total species of Phragmites australis rhizosphere fungi is 1.2times than those without vegetation covering,and the quantity is 4 times of non-vegetation soil.A total of 8 strains of highly salt tolerant fungi were isolated from the rhizosphere soil of Phragmites australis,they are Aspergillus versicolor,Penicillium aurantiogriseum,Aspergillus terreus,Aspergillus niger,Penicillium jensenii,Penicillium brevicompactum,Penicillium corylophilum and Aspergillus ochraceus.The Penicillium brevicompactum,Penicillium corylophilum and Aspergillus ochraceus' salinity resistant reached 18% or even20%.Spring,summer,autumn and winter with Aspergillus ochraceus have the highest salt tolerance.Screening of four plant pathogenic bacterias antagonistic bacteria by the method of plate confrontation,the plant pathogenic bacterias are Alternaria alternata,Alternaria tenuissima,Fusarium oxysporum and Fusarium solani.There are seven species of Alternaria and Fusarium solani antagonistic bacteria,five species of Alternaria tenuissima antagonistic bacteria and nine species of Fusarium oxysporum antagonistic bacteria.Among these antagonistic bacteria,Aspergillus ochraceus,Scopulariopsis candida and Penicillium variabile can inhibit the occurrence of two or more plant pathogens.what the article different from previous studies is that the spring,summer,autumn and winter seasons are used as variables toanalyze the diversity of culturable fungi in the rhizosphere soil of Phragmites australis,and in the rhizosphere of Phragmites australis,the culturable fungi were selected as antagonistic bacteria for plant pathogens,control of plant diseases by fungi in the rhizosphere of itself.Fully embodies the idea of using plants for plants,to lay the foundation for future research in this area.