Downy Mildew of Rocket (Eruca vesicaria ssp. sativa) and Leaf Mustard (Brassica juncea) Caused by Peronospora parasitica

Abstract

Downy mildew of rocket (Eruca vesicaria ssp. sativa) and leaf mustard (Brassica juncea) occurred in Tako, Chiba on July 2003. Both causal agents were identified as Peronospora parasitica (Persoon: Fries) Fries. Physiological specialization of both fungi were different from each other and those of already-known P. parasitica. This is the first report on these diseases in Japan.