Investigation Of Disease Types Of Processing Tomato In Shihezi Area And Preliminary Study On Tomato Early Blight Of The Virus Strain AS24

Early blight is one of the most important diseases of processing tomato in Xinjiang,which seriously threatens the yield and quality of processing tomato.Fungal virus(mycovirus)is a virus that is widely found in fungi and can infect fungi and reproduce in fungal cells,because of its can lead to weakened host pathogenicity,have certain application value in biological control of plant fungal diseases.In this paper,an investigation was made on the incidence of Processing Tomato Early Blight in Bole,Kuitun and Shihezi regions,and sample collection and pathogen isolation,A number of Early Blight Strains with fungal viruses were obtained,selecting one strain with fungal virus strain AS24 of abnormal phenotype was studied,obtains the following research achievements:1.Field investigation on common diseases of processing tomato in the area of Shihezi,found that there are nine kinds of field diseases of processing tomato in Shihezi area,respectively: Bacterial speck,Early blight,Orobanche,Virus disease,Navel rot,Sunscald,Cotton blight,Leaf mold,Powdery mildew.2.The processing tomato early blight disease samples collected from Kuitun and Bole Region were separated and purified,a total of 85 strains of Alternaria solani were isolated,and by extracting ds RNA from these strains to detect the virus carrying rate,the results showed that among the 85 strains of the pathogen,there were 23 strains detected Contain fungal virus,the virus carrying rate was 27%.3.Study on the biological characteristics of the strain AS24 carrying fungal virus,including colony morphology,growth rate,sporulation,biomass production and pathogenicity.The results showed that the growth rate of fungal strain AS24 was slow,the colony morphology was abnormal,and the edge was irregular,The conidial production and biomass production were less than that of the avirulent strain WD24-23;Fungal virus strains of the AS24 after inoculation in tomato leaves,the lesion is small,Strain AS24 in tomato leaves after inoculation,the lesion is small,to compared with the results of inoculation with avirulent strain WD24-23,the pathogenicity was weak.The results showed that the fungal virus had some effects on the growth,reproduction and pathogenicity of the host.4.Two dsRNA bands were detected in the mycelia of the pathogenic strains of AS24 with weak pathogenicity,the size of virus component 1(dsRNA-L)is about 5.5 kb,the size of virus component 2(dsRNA-S)about 1.7 kb.Conducted the random primers of the two different size components dsRNA bands were on cDNA cloned and analyzed.The results show that the virus component 1(dsRNA-L)and the HvV190 S virus(which have been reported in the genus of the Totiviridae-Victorivirus)of the partial sequence the similarity was 64%,Therefore,it is preliminarily judgment that the virus belongs to the family of Totiviridae;However,there was no correlation between the sequence of the virus component 2(ds RNA-S)and the sequence of the reported virus,it remains to be further studied on attribution.