关键词: 刀孢蜡蚧菌, 初始接菌量, 温度, 碳源, 氮源

Abstract: Lecanicillium psalliotae is an important entomopathogenic fungus widely used in biological pest control. In order to determine the optimal culture conditions of the fungus, an optimization was performed for the L. psalliotae HFLP006 strain in this study by comparing the spore production of the fungus under different medium, initial inoculation densities, temperatures, carbon and nitrogen sources. The results showed that, the highest production of spores (2.83×10⁹ spores/mL) was obtained when the fungus was inoculated in SDAY medium, under a 8% inoculation density, and cultured for eight days. The optimal temperature for HFLP006 strain was 26℃. By using mannitol and glucose as carbon sources can yield highest amount of spores, which were 1.28×10⁹ and 1.25×10⁹ spores/mL, respectively. In addition, the difference on the spore production between the two carbon sources was not significant. The highest yield of spores, 9.48×10⁸ spores/mL, was obtained by using yeast extract as nitrogen source, and significantly higher than those using other nitrogen sources. The pathogenicity of HFLP006 strain (1×10⁷ spores/mL) on the geen peach aphid, Myzus persicae, was tested and the average adjusted mortality of aphids was 80.73% at seven days after the treatment. The findings from this study are of significant importance not only to large-scale industrial production of HFLP006 strain, but also for the application of the fungus in biological pest control.

Key words: Lecanicillium psalliotae, initial inoculation density, temperature, carbon source, nitrogen source