A novel method was developed to use glutinous broomcorn millets (Panicum miliaceum L.) as solid substrate to make cultures of the entomophthoralean fungus Pandora delphacis specifically pathogenic to planthoppers, lea...A novel method was developed to use glutinous broomcorn millets (Panicum miliaceum L.) as solid substrate to make cultures of the entomophthoralean fungus Pandora delphacis specifically pathogenic to planthoppers, leafhop-pers and aphids. Steamed millets with water content of 45% were inoculated with a liquid culture of P. delphacis at a ratio of 20% (v/w) and then incubated at 25℃ and L:D 12:12. The millets cultured for 3—17 d exhibited high potential for co-nidial production. The 5-d-old millet culture sporulated most abundantly, discharging up to 17.12 (1.31) 104 conidia/ millet. The cultures incubated for 7—11 d also had a satis-factory sporulation capability, yielding 13.00—13.90 104 conidia/millet. Compared to 2.32 (0.34) 104 conidia dis-charged from each of Myzus persicae adults killed by P. del-phacis and a ≤60-h duration of sporulation, each of the millets cultured for 5—11 d produced 5.6—7.4 times more conidia with an over doubled duration for conidial discharge (144 h). Among 106 M. persicae adults exposed to the shower of conidia discharged from the cultured millets, a total mor-tality of 69.8% caused by P. delphacis infection was observed within 7 d after exposure, but no death was attributed to the fungal infection in the aphids unexposed. The results indi-cate that the millet cultures of P. delphacis are biologically similar to aphid cadavers killed by the same fungus. Due to the superiority of the cultured millets to the cadavers in sporulation potential and duration, the method for making cultures of P. delphacis on the broomcorn millets is highly recommended for use in study of entomophthoralean fungi for microbial control. This is the first report on the success of the solid culture of Pandora species on cereals.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.30070514)the Special Fund for Graduate Study Programs in Chinese Universities(Grant No.200203335041)the‘Cheung Kong Scholars Programme’,Ministry of Education,China.
文摘A novel method was developed to use glutinous broomcorn millets (Panicum miliaceum L.) as solid substrate to make cultures of the entomophthoralean fungus Pandora delphacis specifically pathogenic to planthoppers, leafhop-pers and aphids. Steamed millets with water content of 45% were inoculated with a liquid culture of P. delphacis at a ratio of 20% (v/w) and then incubated at 25℃ and L:D 12:12. The millets cultured for 3—17 d exhibited high potential for co-nidial production. The 5-d-old millet culture sporulated most abundantly, discharging up to 17.12 (1.31) 104 conidia/ millet. The cultures incubated for 7—11 d also had a satis-factory sporulation capability, yielding 13.00—13.90 104 conidia/millet. Compared to 2.32 (0.34) 104 conidia dis-charged from each of Myzus persicae adults killed by P. del-phacis and a ≤60-h duration of sporulation, each of the millets cultured for 5—11 d produced 5.6—7.4 times more conidia with an over doubled duration for conidial discharge (144 h). Among 106 M. persicae adults exposed to the shower of conidia discharged from the cultured millets, a total mor-tality of 69.8% caused by P. delphacis infection was observed within 7 d after exposure, but no death was attributed to the fungal infection in the aphids unexposed. The results indi-cate that the millet cultures of P. delphacis are biologically similar to aphid cadavers killed by the same fungus. Due to the superiority of the cultured millets to the cadavers in sporulation potential and duration, the method for making cultures of P. delphacis on the broomcorn millets is highly recommended for use in study of entomophthoralean fungi for microbial control. This is the first report on the success of the solid culture of Pandora species on cereals.
