ARS | Publication request: Detection of Candidatus Liberibacter solanacearum in individual and composite samples of the potato psyllid, Bactericera cockerelli Sulc.

Submitted to: Southwestern Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 14, 2011
Publication Date: July 1, 2011
Citation: Crosslin, J., Lin, H., Munyaneza, J.E. 2011. Detection of Candidatus Liberibacter solanacearum in individual and composite samples of the potato psyllid, Bactericera cockerelli Sulc.. Southwestern Entomologist. 36: 125-135.

Interpretive Summary: The zebra chip disease of potatoes is an emerging problem for potato growers in the United States, Central America, and New Zealand. The disease causes potato tubers to unacceptably dark when they are processed for potato chips. A bacterium called Candidatus Liberibacter solanacearum is associated with zebra chip disease and is transmitted to potatoes by the potato psyllid. Much work has been done on this insect and the ZC disease and many laboratories currently test for the bacterium using PCR. We have been testing individual and composite samples of B. cockerelli for the bacterium as part of an ongoing investigation of the incidence of Ca. L. solanacearum in potato psyllids collected in the south-central and south-western US. Here we report that the bacterium can be reliably detected in nucleic acid extracts prepared from composite samples of one infected psyllid combined with nine liberibacter-free psyllids by both conventional and quantitative real-time PCR. This ability has implications for increased testing of psyllid populations for the bacterium in efforts to predict the threat of developing serious zebra chip disease as a result of psyllid infestations

Technical Abstract: ‘Candidatus Liberibacter solanacearum’ is the putative causal agent of zebra chip disease of potato and is transmitted by the potato psyllid, Bactericera cockerelli Sulc. Much work has been done on this insect-pathogen-plant system and several laboratories currently test for the bacterium using PCR. We have been testing individual and composite samples of B. cockerelli for the bacterium as part of an ongoing investigation of the incidence of Ca. L. solanacearum in potato psyllids collected in the south-central and south-western US. Here we report that the bacterium can be reliably detected in nucleic acid extracts prepared from composite samples of one infected psyllid combined with nine liberibacter-free psyllids by both conventional and quantitative real-time PCR. This ability has implications for increased testing of psyllid populations for the bacterium in efforts to predict the threat of developing serious zebra chip disease as a result of psyllid infestations.