The first report of bacterial streak and rot of onion caused by Pseudomonas viridiflava in Japan.

In March 2020, a bacterial streak and rot symptom was observed on the onion (Allium cepa L.) leaves in Akita Prefecture of Japan. On the beginning, oval and dark-greenish water-soaked lesions with grayish-white necrotic center, 2-3 mm in diameter, appeared on the middle or the tip of upper leaves.

sp. nov., a pathogen causing soft rot of onion in Japan.

Six phytopathogenic bacterial strains, MAFF 301512, MAFF 301513, MAFF 301514, MAFF 301515, MAFF 301516 and MAFF 301517, were isolated from soft rot lesions of onion ( L.) in Japan. The cells were Gram-reaction-negative, aerobic, non-spore-forming, motile with one or two polar flagella and rod-shaped.