Plant Pathology (2018) 67, 1220-1230

M.T. Andersen, M.D. Templeton, J. Rees-George, J.L. Vanneste, D.A. Cornish, J. Yu, W. Cui, T.J. Braggins, K. Babu, J.F. Mackay and E.H.A. Rikkerink (2018)
Highly specific assays to detect isolates of Pseudomonas syringae pv. actinidiae biovar 3 and Pseudomonas syringae pv. actinidifoliorum directly from plant material
Plant Pathology 67 (5), 1220-1230
Abstract: Pseudomonas syringae pv. actinidiae (Psa) is responsible for bacterial canker of kiwifruit. Biovar 3 of Psa (Psa3) has been causing widespread damage to yellow- and green-fleshed kiwifruit (Actinidia spp.) cultivars in all the major kiwifruit-producing countries in the world. In some areas, including New Zealand, P. syringae pv. actinidifoliorum (Pfm), another bacterial pathogen of kiwifruit, was initially classified as a low virulence biovar of Psa. Ability to rapidly distinguish between these pathovars is vital to the management of bacterial canker. Whole genome sequencing (WGS) data were used to develop PCR assays to specifically detect Psa3 and Pfm from field-collected material without the need to culture bacteria. Genomic data from 36 strains of Psa, Pfm or related isolates enabled identification of areas of genomic variation suitable for primer design. The developed assays were tested on 147 non-target bacterial species including strains likely to be found in kiwifruit orchards. A number of assays did not proceed because although they were able to discriminate between the different Psa biovars and Pfm, they also produced amplicons from other unrelated bacteria. This could have resulted in false positives from environmental samples, and demonstrates the care that is required when applying assays devised for pure cultures to field-collected samples. The strategy described here for developing assays for distinguishing strains of closely related pathogens could be applied to other diseases with characteristics similar to Psa.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Joel L. Vanneste, Matthew D. Templeton

Research topic(s) for pests/diseases/weeds:
identification/taxonomy
surveys/sampling/distribution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Pseudomonas syringae pv. actinidiae	Kiwi (Actinidia)	New Zealand
	Pseudomonas syringae pv. actinidifoliorum	Kiwi (Actinidia)	New Zealand