| Popis: |
Internal stem and root tissues of pear trees were sampled for presence of Pseudomonas syringae at seven orchards in Oregon. Isolates positive for fluorescence (F+) and negative for cytochrome oxidase reaction (Ox−) were defined as P. syringae. Endophytic F+ Ox− strains occurred in 84% (57/68) of the trees. Eighty-one percent (191/235) of the F+ endophytic stains were Ox−. A total of 159 and 32 P. syringae strains were found in root and stem tissues, respectively. The endophytic P. syringae strains varied with respect to ice nucleation activity, induction of hypersensitive response on tobacco, pathogenicity on pear and cherry fruitlets, and genomic DNA fingerprinting (...) |
