莱氏绿僵菌Mr006鉴定及对草地贪夜蛾致病力OA北大核心CSTPCD

The pathogenic Metarhizium rileyi were collected from diseased Spodoptera frugiperda for the purpose of enriching the entomopathogenic fungi resource in Anhui for green prevention and control of S.frugiperda.In this study,the strain Mr006 was identified using morphological characterization and ITS-rDNA sequence analysis,and the pathogenicity of the strain to the larvae,prepupae,and pupae of S.frugiperda and the field application efficiency were evaluated.The strain Mr006 was identified as M.rileyi and showed pathogenicity in the larvae and pupae of S.frugiperda.A spore concentration of 1 X 107 spores/mL achieved a corrected mortality of 91.16％,88.38％,70.71％,53.03％,22.73％,and 76.26％in the 1st to 5th instar larvae and pupae,respectively.LC50 values to the 1st to 5th instar larvae and pupae were 3.55X104,8.23X 104,3.63X106,4.16X 107,4.23X 108 and 2.57 X105 spores/mL,respectively.LT50 values is negatively correlated with spore concentration and positively correlated with larval instar.At a spore concentration of 1 × 108 spores/mL,LT50 values to the 1st to 5th instar larvae and pupae were 3.47,3.94,4.90,6.73,9.01 and 4.02 d,respectively.In the field at 20 days after application,the strain achieved a control of over 64％and showed a good persistence against S.frugiperda.The current results indicate the strain Mr006 is highly pathogenic to S.frugiperda and of high biological control potential for further development.