Preliminary results on susceptibility of Actinidia sp. genotypes against bacterial canker

In the frame of a CRPV project, a study was conducted on 14 genotype selections of Actinidia spp. to evaluate their susceptibility to the bacterial canker. Under controlled conditions experimental inoculations were carried out on young leaves of kiwifruit plants grown in pots, by spraying a calibrated water suspension of a local, virulent strain (isolated in 2013) of Pseudomonas syringae pv. actinidiae. Actinidia chinensis 'Belen' was used as positive control as the most susceptible genotype and non-inoculated plants were used as negative control. The disease assessments were performed 21 days after the inoculation with the pathogen. The disease severity (mean of leaf spots per treatment) allowed to detect one A. chinensis selection showing low a susceptibility that is comparable to that of selections belonging to A. arguta, A. hemsleyana and A. eriantha. No selections were found more susceptible than 'Belen', but among all selections, one resulted significantly comparable with it. Eight selections were found to be moderately susceptible, and three of them (A. chinensis selections) were apparently less susceptible than A. deliciosa 'Hayward', known having intermediate susceptibility.