A new bacterial disease has been observed on mioga (Zingiber mioga (Thunb.) Rosc.) since 1999, in Kochi Prefecture, Japan. Leaves wilted, curling under toward the center of midrib, yellowed, and the whole plant finally died. Bacterial exudate was observed at the cut edges of the pseudostem. The creamy-whitish bacteria that were isolated were pathogenic to mioga and ginger and were identified as Ralstonia solanacearum race 4 strains biovar 4 based on bacteriological characteristics. The name bacterial wilt of mioga is proposed for the disease.
In April 2004, dwarf gentian (Gentiana sp.) with chlorotic mottle and necrotic spot was found in Iwate Prefecture, Japan. The isolated virus infected six plant species of four families after mechanical inoculation. This is the first report of Impatiens necrotic spot virus (INSV) on gentian and we propose the name necrotic mottle disease of gentian.