Identification,Integrated Control Of Colletotrichum Scovillei And Differentially Expressed Genes In Pepper After Interaction Between Colletotrichum Scovillei And Pepper

Pepper is an important vegetable crop in China.Anthracnose is one of the main diseases of pepper and has a serious impact on pepper.This experiment identified the the anthracnose pathogen of Tianshui pepper of Gansu Province,determined the differential expression of the genes infecting pepper by Colletotrichum scovillei.Furthermore,the chemical fungicide and antagonistic endophytic bacteria were screened against Colletotrichum scovillei,and identified the antagonistic endophytic bacteria,and obtained the following conclusions:1 Identification of the pathogen and biological characteristics of capsicum anthracisThe colonies of anthracnose pathogen of Tianshui,Pepper in Gansu province is round,fluffy,and the primary hypha was milky white,and then the center of the colonies turns grayish green,the conidia are oval or cylindrical,single spore,colorless,containing oil droplets,slightly pointed at the top,separated The spore size is 11.24²5.94μm×4.27⁸.85μm,the acervulus is cluster-like and transparent,with a size of 11.28μm×13.10μm.The hyphae are bifurcated acute angle branches,seperate,conidiophores cylindrical,colorless,spores at the top,typical of Colletotrichum.Combining with the analysis sequences of gene ITS,TUB2,CHSI,ACT and GAPDH,the pathogen was identified as Gauvil anthrax.Colletotrichum scovillei.The biological characteristics of the cells were determined to be suitable for the growth of mycelium at 25°C,suitable for sporulation and spore germination at 35°C,the most suitable for mycelial growth and spore germination is at pH 6,and the best sporulation is at pH 8.The suitable light conditions for growth,sporulation and spore germination were all darkness,the carbon source was mannitol,fructose and rhamnose respectively,which was the most favorable for mycelial growth,sporulation and spore germination as well as the sporulation and spore germination for growth.2 Screening of high-efficiency control agents for anthraxThe difenoconazole has the highest inhibitory activity against the growth of mycelium and spore germination of anthrax,and the minimum EC₅₀ values were 0.0254μg/m L and 0.0216μg/m L respectively.The combination of flusilazole has the highest inhibitory activity against the mycelial growth of Anthracnose,with an EC₅₀ of only 0.1882μg/m L,and the highest inhibitory activity against spore germination is the combination of difenoconazole and pyraclostrobin.And the EC₅₀ value is 0.0541μg/m L.3 Isolation,screening and identification of endogenous antagonistic bacteria58 endophytic bacteria were isolated from pepper leaves by tissue separation,and the inhibition rate of 25 strains to anthracnose was more than 60%.The reported rates of strains L1-7and L3-5 were 79.72%and 80.00%respectively,both of them have nitrogen fixation and IAA production ability,and they could also tolerate the condition with high salt,according to the observation of culture traits,morphological characteristics,and the sequence analysis of gene16S rDNA Bacillus specific primer gyrB,two endophytic bacteria were separated,and it was identified as Bacillus amyloliquefaciens and Bacillus velezensis.4 Analysis of gene expression profile of pepper under the induced of anthraxA total of reads 49418873 were obtained through high-throughput sequencing,among which Clean reads were 48719455,GC content of 43.44%,differential expression gene were 33070,up-regulated expression and down-regulated expression were 13304,and 19966 respectively,inoculation 0 h compared with other time points,5 groups produced differences The differential expressed genes were 7269,6274,6843,6871 and 5795 respectively,and the number of up-regulated genes was 2879,2484,2918,2825 and 2198 respectively.Significant enrichment of differential genes GO functional analysis showed that the number of GO entries enriched into biological processes,molecular functions and cell components was 441,192 and 166respectively.The main enrichment terms were glucan metabolism process,cell polysaccharide metabolism.Process,isoprenoid biosynthesis process,single biosynthesis process,pigment binding,oxidoreductase activity,acting as donor on iron-sulfur protein,catalytic activity,cystic cavity,chloroplast envelope and cytosolic small ribosome Subunits and other pathways.Differently expressed genes are significantly enriched in 23 pathways,and the main pathways were ribosomes,phenylpropanoid biosynthesis,glycolysis or gluconeogenesis,glutathione metabolism,starch and sucrose metabolism,amino sugars,nucleotide sugars and Metabolic pathways etc.,83 co-expressed genes were obtained,6 of which were involved in more than 2pathways,2 of which were up-regulated,43 co-expressed genes were screened in the pathway of plant-pathogen interaction,20 of which were up-regulated.The results preliminarily revealed that the differential expression of the interaction between pepper and anthracnose at the transcriptional level,which provided a theoretical basis for further exploring the pathogenic genes of pepper anthracnose and the pathogenic mechanism.