Submitted to: Plant Disease
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/21/2013
Publication Date: 5/29/2013
Citation: Aguilar, E., Sengoda, V.G., Bextine, B., Mc Cue, K.F., Munyaneza, J.E. 2013. First report of 'Candidatus Liberibacter solanacearum' associated with psylllid-affected tobacco in Honduras. Plant Disease. http://dx.doi.org/10.1094/PDIS-04-13-0453-PDN. Interpretive Summary: Liberibacter is an economically important bacterium that severely damages potato, tomato, pepper, and other solanaceous crops. This plant pathogen is transmitted to these crops by the potato psyllid, a serious insect pest in North and Central America and New Zealand. Researchers at USDA-ARS Wapato, WA and Albany, CA, University of Texas, and Zamorano University in Honduras discovered that this plant pathogen severely affects tobacco and has caused significant losses to the tobacco industry in Honduras. This information will help tobacco producers reduce damage due to this pathogen by effectively controlling the potato psyllid, its insect vector.
Technical Abstract: Tobacco plants with symptoms resembling those associated with the psyllid Bactericera cockerelli and the bacterium “Candidatus Liberibacter solanacearum” (Lso) were observed in April of 2012 in heavily B. cockerelli-infested commercial fields in the Department of El-Paraíso, Honduras; all cultivars grown were affected, at about 5 to 80% symptomatic plants per field. B. cokerelli is a serious pest of solanaceous crops in U.S., Mexico, Central America, and New Zealand and has been shown to transmit Lso to potato, tomato, and other solanaceous species. Symptoms on affected plants include apical leaf curling and stunting, overall chlorosis and plant stunting, young plant deformation with cabbage-like leaves, wilting, internal vascular necrosis of stems and leaf petioles, and production of poor leaf quality. Tobacco plant samples were collected from one psyllid-infested field in the municipality of Trojes. Total DNA was extracted from leaf tissues of a total of 13 plants, including eight symptomatic plants and five asymptomatic plants with the CTAB buffer extraction method. The DNA samples were tested by PCR using specific primer pairs OA2/OI2c and OMB 1482f/2086r, to amplify a portion of 16S rDNA and the outer membrane protein gene of Lso, respectively. All eight (100%) symptomatic plant samples were positive for Lso with both pairs of primers. No Lso was detected in the asymptomatic plants. To our knowledge, this is the first report of Lso associated with tobacco in Honduras, where this cash crop is economically important. This information will help tobacco producers to reduce damage due to this pathogen by effectively controlling the potato psyllid, its insect vector.