Mass production of conidia of Sydowia japonica, a candidate of male-strobilus specific biocontrol agent for preventing the pollen dispersal of Cryptomeria japonica

摘要

Reduction of the pollen counts of Cryptomeria japonica is required for control of Japanese cedar pollinosis in Japan. The fungal parasite Sydowia japonica is under consideration as a biocontrol agent for male strobili of C. japonica. This organism hasbeen shown to be virulent only against male strobili and seems to be a potential candidate for the control of the pollen dispersal. However the fungus has never produced sufficient numbers of inoculum on the artificial solid media for the application inthe field yet. Here we report a series of experiments for mass production of conidia of S. japonica in artificial media. No teleomorph was induced on any artificial medium but conidia were easily produced on several media. Liquid medium based on Czapek-Dox and yeast extract was most useful for the production of the conidia. Additionally, culture condition was optimized for the rapid and mass production of the conidia. This study contributed to development of the application of S. japonica as male strobilus-specific bioherbicide.