Survival of Pseudomonas syringae pv. actinidiae on Cryptomeria japonica, a non-host plant used as shelter belts in kiwifruit orchards.

Pseudomonas syringae is a group of plant pathogenic bacteria that can survive in the environment outside their host plants. The environment can therefore act as a reservoir for the pathogen. The goal of this study was to determine whether Cryptomeria japonica, one of the most common plant species used in the Bay of Plenty as shelter belts between blocks of kiwifruit, could harbour Pseudomonas syringae pv. actinidiae (Psa), the causal agent of bacterial canker of kiwifruit. To determine whether C. japonica could constitute a source of inoculum, potted plants maintained in a PC2 laboratory were inoculated with different concentrations of a streptomycin-resistant derivative of Psa. Populations of Psa were determined at regular intervals up to 18 days after inoculation. In all experiments, populations of Psa declined over time. Therefore, under laboratory conditions, C. japonica did not support the multiplication of the pathogen.