ARS | Publication request: Endophytic bacteria in potato tubers affected by zebra chip disease

Submitted to: American Phytopathology Society
Publication Type: Abstract Only
Publication Acceptance Date: May 20, 2011
Publication Date: June 24, 2011
Citation: Liu, Q., Chen, J., Munyaneza, J.E., Civerolo, E.L. 2011. Endophytic bacteria in potato tubers affected by zebra chip disease. American Phytopathology Society. 101:S108.

Technical Abstract: Potato zebra chip disease (ZCD) could drastically reduce quality and value of all market classes of potato, costing growers and processors millions of dollars in losses in North America. Endophytic bacteria colonize the internal tissue and could have both positive and negative effects on host plants. In potato, there has been research on endophytic bacteria but few were carried out in the context of ZCD. In this study, endophytic bacteria in ZCD affected potato tubers (Cultivar Atlantic), defined by the symptom of phloem necrosis and PCR detection of “Candidatus Liberibacter solanacearum”, were analyzed. A total of 85 bacterial strains belonging to 17 bacterial genera were isolated by in vitro cultivation. ZCD tubers had significantly more culturable endophytic bacterial species than non-ZCD tubers. Paenibacillus sp., Microbacterium sp., Brachybacterium sp., Staphylococcus sp., Stenotrophomonas sp. and Klebsiella sp. were only isolated from ZCD potato tubes, while Bosea sp., Sphingopyxis sp., Sphingomonas sp. and Nocardia sp. were only isolated from non-ZCD potato tubers. PCR experiments using specific primers further confirmed the association of Microbacterium sp. to ZCD tubers and Bosea sp. to non-ZCD tubers. Scanning electron microscopy revealed bacteria with morphology of bacilli, coci, and pleomorphic in the phleom tissue of potato tubers.