Isolation And Identification Of Anthracnose Pathogen From Camellia Yuhsienensis H.H.Hu And Analysis Of Its Host Interaction

Camellia oleifera Abel is an important woody oil tree species in China and it is one of the world’s four largest woody edible oil plants.It has high economic value,edible value,environmental value and medicinal value.But in the C.oleifera industry,C.oleifera diseases and pests are widespread and relatively serious.Anthracnose of C.oleifera has always been one of the most important diseases of Coleifera.In this study,the pathogen causing anthracnose of Coleifera was studied.Using biological methods,the pathogens of anthracnose of Camellia yuhsienensis H.H.Hu were isolated and identified,and the biological comparison and analysis of the Colletotrichum of C.yuhsienensis and common C.oleifera in Youxian county,as well as the interaction between the pathogens of anthracnose of C.oleifera and host C.oleifera related protein analysis.The main experimental results are as follows:(1)Isolation and identification of anthracnose pathogen of C.yuhsienensisA total of 100 sample strains of C.yuhsienensis anthracnose pathogens were isolated from C.yuhsienensis diseased leaves with typIcal C.oleifera anthracnose.After purification of these sample strains,biomorphological characteristics of the sample strains,and molecular identification studies,it was found that there were 5 strains of 4 species of Colletotrichum of Coleifera that caused the anthracnose of C.yuhsienensis.They are YX2-5-2 of C.fruticolade,2YX-3-1 and 2YX-8-1-2 of C.gloeosporioides,2YX-5-1 of C.camelliae and 2YX-8-1-2 of C.siamense,respectively.The isolation rate of Colletotrichum of C.oleifera is as low as 5%,but there are many types of Colletotrichum which can cause anthracnose of C.yuhsienensis.(2)A comparative study on the biology of Colletotrichum between common C.oleifera in Youxian County and the C.yuhsienensisThrough a biological characteristics comparison of the Colletotrichum of common C.oletfera in Youxian county and C.yuhsienensis,it was found that there were significant differences in the Colletotrichum of C.oleifera from two different host sources.Compared with the pathogenicity of different strains of the two,after the inoculation of the pathogens on the fresh leaves of common C.oleifera for 5 days,the average lesion diameter formed by the pathogens of anthracnose of common C.oleifera in Youxian county was 11.63mm,which was stronger than that the average lesion diameter formed by pathogens of anthracnose of C.yuhsienensis was 10.37mm.Compared with the spore-forming ability of different strains of the two,the average spore-forming ability of the pathogens of anthracnose of common C.oleifera in Youxian county is 7.40×107,which is stronger than the average spore-forming ability of the pathogens of anthracnose of C.yuhsienensis is 5.44×107.Compared with the temperature effect of different strains of the two on the growth of the pathogens of anthracnose of C.oleifera,the average optimum temperature of the pathogen of anthracnose of common C.oleifera in Youxian county is around 30℃,while the average optimum temperature of the pathogen of anthracnose of C.yuhsienensis is around 28℃.Compared with the effects of different carbon and nitrogen sources on the growth of the pathogens of anthracnose of C.oleifera.The average diameter of colonies formed by the average use of different carbon sources in the pathogen of anthracnose of common C.oleifera in Youxian county is 30.05mm,which is stronger than the average utilization of the pathogens of anthracnose of C.yuhsienensis is 27.91mm.The average diameter of the colonies formed on the average utilization of different nitrogen sources is 23.64mm,but it is weaker than the average utilization of the pathogens of anthracnose of C.yuhsienensis,which is 25.43mm.Compared with the effect of different strains of the two on the growth of the pathogens of anthracnose of C.oleifera at different pH,there is also a difference between the pathogen of anthracnose of common C.oleifera in Youxian county and C.yuhsienensis.It shows that the Colletotrichum of C.oleifera from different host sources,even the same Colletotrichum,are different.The Colletotrichum of C.oleifera may have a preference for the varieties of C.oleifera.(3)Correlation protein analysis of the interaction between the pathogens of anthracnose of C.oleifera and the host C.oleiferaBy using bioinformatics to analyze the related proteins of the interaction between the pathogens of anthracnose of C.oleifera and the host C.oleifera,it was found that the amino acid sequences encoded by the autophagy-related proteins 8 of the C.fructicola and C.gloeosporioides of C.oleifera are 165 and 121,respectively.The pI and Mw values were 9.06,19111.12 and 6.75,14041.15,respectively.The maximum and minimum values of protein hydrophobicity were 2.833,-2.922 and 2.200,and-2.922,respectively.The transmembrane domains of the protein were outside the membrane,respectively.It shows that even if the same genus of Colletotrichum,different Colletotrichum and the corresponding proteins related to interaction are also different.It was found that the fatty acid desaturase 2 proteins of C.oleifera and C.oleifera cultivar Huashuo encoded amino acid sequences of 383 and 382,respectively.pI and Mw values were 8.43,44228.06 and 8.07,44357.97,respectively.The maximum and minimum values of protein hydrophobicity were 2.656,-2.933 and 2.733,-2.833,respectively.The transmembrane domains of the protein are 3 domains outside the membrane,4 transmembrane helix structures,2 domains inside the membrane,respectively.The protein domains have four transmembrane domains region,respectively,and the same transmembrane region in amino acid sequence 82-104.It shows that even if they belong to the same genus of C.oleifera,there are differences in the corresponding proteins related to interaction among different C.oleifera varieties.The results showed that the interaction between the pathogens of anthracnose of C.oleifera and the host C.oleifera might have the specificity of the pathogen and the host,respectively.