北海道におけるネギ葉枯病菌の菌種構成

抄録

In 2005 and 2007,44 isolates were collected from 23 fields where the leaf blight of Welsh onion was occurring,in Hokkaido. All the isolates were observed for their morphological characteristics and tested for their pathogenicity to Welsh onion using the wound and nonwound inoculation method. Forty-one isolates were identified to be Stemphylium vesicarium（Wallroth）Simmons and three isolates to be S. botryosum Wallroth. From these results, S. vesicarium was confirmed to be the major causal agent of this disease in Hokkaido. All 44isolates showed pathogenicity to Welsh onion determined using the wound inoculation method, however,only 22 isolates showed pathogenicity determined using the nonwound inoculation method. This result suggests that S. vesicarium and S. botryosum have a weak pathogenicity to Welsh onion.