Fig. 4.

Pseudomonas syringae pv. actinidiae population in A. chinensis var. deliciosa plants after infection via different entry points. a Epiphytic and endophytic Psa population in buds at different phenological stages: swollen (BBCH 01), open (BBCH 07) and with emerging leaves (BBCH 09) measured in the first 2 weeks. Experiments were performed in screenhouse without controlled environmental conditions. Closed (BBCH 00) or swollen (BBCH 03) [30] buds were inoculated by applying for 24 h a cotton plug soaked in bacterial suspension. Epiphytic and endophytic population were assessed 10 days after inoculation. Experiments was performed on five replicates of 6 bud each. b Incidence of Psa endophytic population in kiwifruit tissues after inoculation of lenticels. The experiment was performed on five replicates of four lenticels each. c Endophytic Psa population after inoculation of leaf abscission scars. Both natural abscission scars (autumn) and mechanically induced ones (late summer) were inoculated. Experiment was performed on six replicates of six scars each. d Psa endophytic population in 3-cm-long wood samples after inoculation of pruning cuts with a Psa suspension (CFBP7286 at 10⁷ CFU mL⁻¹). To verify the time needed for a complete healing of the pruning cuts, inoculation was performed up to 32 days after the cutting and the re-isolation occurred after 10 days. Experiments was performed on five replicates of three pruned canes per each timepoint. e Scheme of the sampling of A. chinensis var. deliciosa potted plant infected with Pseudomonas syringae pv. actinidiae, in order to evaluate the rate of migration of bacteria in the plant. Psa population was determined in different parts of the plant 3 weeks or 4 months after inoculation in a single point. Average endophytic population in the different branching node or section is also reported. Each plant section was 10 cm long. In all panels, average ± standard error is reported