Absorption of Pseudomonas morsprunorum through Cherry Leaf Scars

The absorption of cells of a cherry strain of Pseudomonas morsprunorum through leaf scars into the leaf traces of cherry cultivar Napoleon was not affected when 10 × more cells of a plum strain were present, although this could inhibit the development of the disease. Ninety per cent of 14C-labelled cherry inoculum was deposited within 2 mm of the entry point, with small amounts extending 25 mm into the host in the presence or absence of the plum strain. Bacteria were observed in regular arrays inside the vessels of the leaf traces, and there was evidence that bacteria migrated from these to other tissues within 5 days of inoculation. No visible damage or changes in the phenolic content of the host were observed during this period.