Screening, Identification and Cultivation Condition Study of Entomopathogenic Fungi of Myzus Persicae

In order to obtain entomopathogenic fungi that have the infection effect on Myzus Persicae, fungal strains were isolated from Myzus Persicae infected by fungus in different tobacco areas in Guizhou Province, the infection rate was determined in the laboratory and the dominant strains were screened and determined by rDNA-ITS sequence. The growth rate method of mycelium was used to explore medium, temperature, light and pH conditions suitable for the growth of the fungi. The results showed that 16 strains of fungi were collected and isolated, and the infection rates of CM-4, CM-11 and CM-15 with strong infection effects were screened out. After 15 days of indoor application, the infection rates of Myzus Persicae reached 68.07%, 69.80% and 72.05% respectively. Three strains of molds, CM-4, CM-11 and CM-15, had the highest homology with Chaetomium aureum, Lecdanicillium attenuatum and Rhizopus arrhizus respectively through BLAST online comparison. CM-11 and CM-15 were suitable for culture in medium E and CM-4 in medium A. The optimum temperature for CM-15 and CM-4 was 25 to 30℃, the suitable light condition for CM-4 and CM-11 was half light and half dark, and the optimum pH was 6 to 7. Studies showed that Chaetomium aureum, Lecdanicillium attenuatum and Rhizopus arrhizus have strong effect on the infection of Myzus persicae, they can be used for biological control of Myzus persicae.