Pacific Northwest, United States the Dryland Agroecosystem of the Inland in Phenazine-Producing Pseudomonas spp. Taxonomy and Distribution of

genes (1, 2). Indigenous phenazine-producing (Phz ) pseu-domonadsareabundantincertainagriculturalsoils(1,3,4),andsuchstrainsinhibitsoilborneplantpathogens(3,4).IntheInlandPacificNorthwestregionoftheUnitedStates(IPNW),Phz pseu-domonadsaregeneticallyandphenotypicallydiverse(5)andpar-ticularly abundant in the low-precipitation zone, where they oc-cur at densities of 10