Cryopreservation of aphid-specific pathogen Pandora nouryi
蚜科专化菌努利虫疠霉菌种超低温储存

The viabilities of entomophthoralean fungi are sensitive to cryopreservation procedures.The efficacy of preservation methods for these fastidious fungi should be evaluated in detail before extensive application.In this study,the primary spores(2-3?105conidia/mL) of an aphid obligate pathogen Pandora nouryi was preserved at-80℃ for 12 months.The routine culture medium of Sabouraud dextrose broth plus 0.1% emulsified sesame oil(SDBS) was selected for culture storation,due to more effective in protecting the fungal spores than ordinary cryoprotectants such as dimethylulphoxide and glycerol.The highest biomass and growth rate were obtained after the preserved spore suspensions were thawed and incubated.Moreover,4% glucose,1% peptone and 1% yeast extracts in the liquid culture played cooperative roles in preserving the isolate under ultracold condition,and the virulence retained stable.After one year preservation,the median lethal concentration of the isolate against Myzus persicae nymphs was estimated as 3.3conidia/mm2 by analysis of multiple-dose bioassay data,consistent with that in the previous repeated report.In a word,-80℃ cryopreservation can be accepted as a good preservation technique for entomophthoralean fungi,and Sabouraud dextrose broth is more suitable as cryoprotectantive medium for P.nouryi than 10% glycerol solution.