Submitted to: American Journal of Potato Research
Publication Type: Abstract Only
Publication Acceptance Date: 3/10/2009
Publication Date: 2/1/2010
Citation: Wanner, L.A. 2010. Local and regional diversity in Streptomyces species causing common scab in North America. American Journal of Potato Research. 87:126.
Technical Abstract: Common scab of potato and other tuber/root crops, caused by a complex of soil bacteria in the genus Streptomyces, is one of the most important potato diseases in North America. Knowledge of the pathogen is fundamental to understanding and alleviating plant disease. To learn what species are found in common scab lesions in North America, more than 1400 isolates were made from scabby potato tubers obtained from multiple locations across the continent, as well as from multiple sites in close geographic proximity. Most potentially pathogenic isolates belonged to four species previously associated with common scab, S. scabies, S. europaeiscabiei, S. stelliscabiei, and a recently-described group that has been called IdahoX. Small numbers of S. acidiscabies, S. turgidiscabies and six additional ribotypes (potentially species) were also found. S. europaeiscabiei was most common in the west and S. scabies predominated in the Midwest. Beyond this geographic trend, species distribution was patchy. Often, a single species predominated in a field while neighboring fields had different species. Genetic variation within species was also evident. Local and regional genetic variation was seen when isolates were genotyped for repetitive sequence element patterns, reflecting the conserved or core genome, and for genes characteristic of the Streptomyces pathogenicity island, reflecting flexible components of the Streptomyces genome. We conclude that common scab is caused by a diverse and dynamic Streptomyces community. This is the largest survey to date of the distribution of common scab-causing species. The collection of Streptomyces isolates is a resource for population biology studies and for tracing the evolutionary history and spread of common scab-associated Streptomyces. (talk AND poster, if possible), Plant Protection, PAA Membership 657).