Author
STOCKWELL, V - Oregon State University | |
Shaffer, Brenda | |
BENNETT, R - Oregon State University | |
LEE, J - Oregon State University | |
Loper, Joyce |
Submitted to: Phytopathology
Publication Type: Abstract Only Publication Acceptance Date: 6/3/2015 Publication Date: 8/1/2015 Citation: Stockwell, V.O., Shaffer, B.T., Bennett, R., Lee, J., Loper, J.E. 2015. Characterization of Pseudomonas syringae from blueberry fields in Oregon and Washington [abstract]. Phytopathology. 105:54.132. Interpretive Summary: Technical Abstract: Bacterial canker, caused by Pseudomonas syringae, is a common disease that kills buds and stems in blueberry fields in Oregon and western Washington. Management is primarily through application of copper; antibiotics are not registered for blueberry. Little is known about the diversity of P. syringae from blueberry or the prevalence of copper or antibiotic resistance. We collected blue-fluorescent, oxidase-negative isolates of P. syringae from blueberry fields in Oregon in 2013 and Washington in 2014. Through MLSA of housekeeping genes (cts, rpoD and gyrB), we found that 50 isolates from Oregon were associated with 5 of the 13 known phylogroups of P. syringae. Representatives of four phylogroups caused disease symptoms on cantaloupe seedlings and three also caused HR on tobacco. Only 1% of 139 isolates from Oregon and Washington were resistant to streptomycin or oxytetracycline. In contrast, 57% of isolates of P. syringae from blueberry in Washington were tolerant of 50 ppm Kasumin, a newly registered antibiotic for crops. Copper resistance in P. syringae from blueberry was common; 55% and 87% of isolates in Oregon and Washington, respectively, grew on CYE medium with 0.32 mM CuSO4. With the emergence of copper-resistance in P. syringae from blueberry, alternative control measures for bacterial canker are needed. |