Occurrence of Bacterial Spot Disease of Tea Caused by Acidovorax valerianellae Gardan, Stead, Dauga and Gillis 2003 in Shizuoka Pref.

A red spot disease has been observed on leaves of a line of tea (Camellia sinensis) in Shizuoka Pref., in 2015. At first glance, the symptoms were similar to bacterial shoot blight caused by Pseudomonas syringae pv. theae (Hori 1915) Young, Dye and Wilkie 1978. But water-soaked lesions around spots were narrower than that observed in bacterial shoot blight, and the margin of water-soaked lesions was unclear. Further, no symptom on petiole has been observed, which was frequently observed as the first major symptom of bacterial shoot blight. Therefore, identification of the causal agent was performed through isolation of pathogenic bacteria, artificial inoculation, physiological tests and phylogenic analysis based on 16S rRNA gene. As a result, it became clear that this disease was identical with bacterial spot of tea caused by Acidovorax valerianellae Gardan, Stead, Dauga and Gillis 2003. This is the first report on the occurrence of this disease outside Kagoshima Pref.