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United States Department of Agriculture

Agricultural Research Service

Research Project: CONTROL OF PATHOGENS IN STRAWBERRY AND VEGETABLE PRODUCTION SYSTEMS Title: Identification of Pseudomonas cannabina pv. alisalensis previously isolated from diseased crucifers in Australia.

Authors
item Rubio, Isael -
item Bull, Carolee

Submitted to: Society for the Advancement of Chicanos and Native Americans in Science
Publication Type: Abstract Only
Publication Acceptance Date: July 23, 2010
Publication Date: September 30, 2010
Citation: Rubio, I., Bull, C.T. 2010. Identification of Pseudomonas cannabina pv. alisalensis previously isolated from diseased crucifers in Australia.. Society for the Advancement of Chicanos and Native Americans in Science. p.75.

Technical Abstract: Pseudomonas cannabina pv. alisalensis causes bacterial blight on crucifers, a severe disease which can reduce crucifer yields and result in economic losses in the US. Prior to the late 1990s P. cannabina pv. alisalensis was not distinguished from the pepper spot pathogen of crucifers, Pseudomonas syringae pv. maculicola, which has been found world-wide. Correctly identifying and distinguishing similar pathogens with different host ranges is crucial for developing effective management strategies and preventing pathogen spread. We hypothesized that strains identified as P. syringae pv. maculicola isolated from diseased crucifers in Australia are P. cannabina pv. alisalensis because they had ITS sequences similar to Pseudomonas cannabina pv. alisalensis. We compared three strains from Australia with the pathotype and other representative strains of P. cannabina pv. alisalensis and P. syrignae pv. maculicola. Bacteriophage PBS1 specifically lyses Pseudomonas cannabina pv. alisalensis. PBS1 was spotted on a soft-agar overlay containing the bacterial test strain, incubated overnight and evaluated for lysis. All three of the strains from Australia were sensitive to PBS1 while P. syringae pv. maculicola was not. Additionally, rep-PCR banding patterns from two Australian strains were identical to P. cannabina pv. alisalensis strains from arugula and radish and not Pseudomonas syringae pv. maculicola. The third Australian strain was similar but not identical to P. cannabina pv. alisalensis. We are currently comparing the pathogens’ host ranges and presence of coronatine biosynthesis genes. These preliminary data supported our hypothesis that at least two strains isolated from crucifers in Australia were Pseudomonas cannabina pv. alisalensis.

Last Modified: 10/30/2014