Occurrence of Bacterial Wilt Disease of Ginger Caused by Ralstonia solanacearum Species Complex in Myanmar
概要
A survey was carried out in November 2021 in Shan State in Myanmar to collect the bacterial wilt of ginger. Ginger plants showing leaf yellowing, and rhizome rotting, which are typical symptoms of bacterial wilt were found in the fields in Heho and Yatsauk townships. Bacterial slime oozed spontaneously from the cut surface of infected pseudostems when soaked in water, indicating the disease was caused by a bacterial pathogen. Isolation was performed using a 2–3–5 triphenyl tetrazolium chloride (TTC) agar medium. The colony morphologies were cream–white with pink center, irregular, and fluidal in most colonies, which are typical characteristics of the colony of Ralstonia solanacearum species complex. After repeating single colony isolation, the bacterial isolates were inoculated to ginger seedlings by leaf clipping. The yellowing lesions observed naturally infected ginger were reproduced on the leaves inoculated with the isolates, and the re-isolation was confirmed. Forty–five isolates of R. solanacearum species complex collected from two different areas were isolated and stocked in sterilized distilled water for further study. This is the first report of bacterial wilt of ginger caused by R. solanacearum species complex in Myanmar.