Bacterial Canker Disease of Wild Actinidia Plants as the Infection Source of Outbreak of Bacterial Canker of Kiwifruit Caused by Pseudomonas syringae pv. actinidiae

Abstract

An attempt was made at isolating the pathogenic bacterium, Pseudomonas syringae pv. actinidiae, on several kinds of actinidia plants for the purpose of identifying the infection source of the bacterial canker of kiwifruit (Actinidia deliciosa), an infection which is peculiar to Japan. Isolates, which were classified as P. syringae pv. actinidiae on the basis of serological characteristics using a monoclonal antibody against pathogenic agents, were isolated on six samples of A. arguta and A. kolomikta, This was out of a total of ninety samples collected from all over Japan. Twenty-two isolates within these causal agents showed some differences in pathogenicity but indicated a susceptibility reaction to actinidia plants. As the bacterial agent was also found to be distributed in Hokkaido, where kiwifruit plants are not found, it was concluded that the bacterial canker pathogen originated on the actinidia plants grown in Japan and was disseminated to kiwifruit vines.