First Report of Bipolaris sp. Leaf Spot of Calathea, Ctenanthe and Maranta in Japan

Abstract

Leaf spot symptoms occurring on the plants Calathea louise Gagnep., C. zebrina (Sims) Lindl., Ctenanthe oppenheimiana (E. Morr.) K. Schum., Maranta leuconeura var. erythroneura Bunt., M. leuconeura var. kerchoviana E. Morr., and M. leuconeura var. leuconeura E. Morr. were detected on the island of Hachijo, an administrative area of the Tokyo metropolitan government. The pathogen isolated from leaf spots present on the above plants was a fungal species in the genus Bipolaris. Calathea, Ctenanthe and Maranta plants inoculated with the Bipolaris sp. produced the same disease symptoms. The inoculation test demonstrated that this fungus was the causal agent of the leaf spot of these plants. This is the first report of this disease in Japan.