Downy mildew of coleus caused by Peronospora belbahrii in Japan

摘要

In April 2007, coleus (Solenostemon scutellarioides) plants cultivated in a greenhouse in Chiba Prefecture, Japan were observed to have poor growth, with yellowing of the adaxial leaf surface and a gray to black downy growth on the abaxial leaf surface. The causal pathogen was identified as Peronospora belbahrii based on its morphology and rDNA-ITS sequences. Uninfected coleus was inoculated with the pathogen, the original symptoms were reproduced, and the isolate was reisolated. This is the first report of downy mildew of coleus in Japan.