Bacterial wilt of geranium and portulaca caused by Ralstonia solanacearum in Japan

New bacterial disease was observed on geranium and portulaca in Miyazaki Prefecture, Japan in 2002. The leaves were wilted and yellowed, and the stem and roots were rotted. Faint discoloration of the vascular bundles were observed. When the cut of the stem was dipped into water, white bacterial ooze was visible. The colony appearance of the isolated bacterium was similar to that of Ralstonia solanacearum. The bacterium was pathogenic to both geranium and portulaca. Its bacteriological properties agreed with those of the standard isolates of R. solanacearum. From these results, the bacterium was identified as R. solanacearum biovar 3. Bacterial wilt of geranium and bacterial wilt of portulaca were proposed for the names of the disease.