Submitted to: European Journal of Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/5/2011
Publication Date: 9/21/2011
Citation: Lin, H., Islam, M.S., Bai, Y., Wen, A., Lan, S., Civerolo, E.L., Gudmestad, N.L. 2011. Genetic diversity of ‘Candidatus Liberibacter solanacearum’ isolates in the United States and Mexico reveled by simple sequence repeat markers. European Journal of Plant Pathology. (DOI 10.1007/s10658-011-9874-3). Interpretive Summary: ‘Candidatus Liberibacter solanacearum’ is associated with potato Zebra Chip (ZC) disease. A new set of eight molecular markers, named simple sequence repeats, was developed and used to characterize genetic relationships among ‘Ca. L. solanacearum’ strains obtained from ZC-affected potato plants in the United States and the Mexico. Results from genetic analyses indicated that ‘Ca. L. solanacearum’ strains in US populations were clustered into two major groups. However, no geographic or host cultivar association was found among strains. This multilocus marker typing system, in combination with epidemiological data, will advance knowledge of genetic diversity and population structure of the bacterium associated with ZC disease.
Technical Abstract: ‘Candidatus Liberibacter solanacearum’ is associated with the Zebra Chip disorder of potatoes. A panel of eight simple sequence repeat (SSR) markers was developed and used to genetically characterize ‘Ca. L. solanacearum’ strains obtained from ZC-affected potato plants in the United States and Mexico. Multilocus SSR markers in this study effectively differentiated genotypes and estimated genetic diversity of ‘Ca. L. solanacearum’ strains. Genotype assignment analyses identified two major lineages of ‘Ca. L. solanacearum’ in the North American populations while only one lineage type was identified in the Mexican population. No clear genetic structure was found among haplotypes based on geographical proximity or host. The high resolution power of the SSR marker system developed in this study provides a useful tool for genotyping closely related strains and tracking sources of the pathogen. Genotype information combined with epidemiological data will advance knowledge of ZC disease and will facilitate development of effective disease management.