|TORRES, GLENDA - Heritage University
|Cooper, William - Rodney
|Swisher Grimm, Kylie
|Munyaneza, Joseph - Joe
|BARCENAS, NINA - Heritage University
Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/28/2015
Publication Date: 11/10/2015
Publication URL: http://handle.nal.usda.gov/10113/61653
Citation: Torres, G.L., Cooper, W.R., Horton, D.R., Swisher, K.D., Garczynski, S.F., Munyaneza, J.E., Barcenas, N.M. 2015. Horizontal transmission of "Candidatus Liberibacter solanacearum" by Bactericera cockerelli (Hemiptera: Triozidae) on Convolvulus and Ipomoea (Solanales: Convolvulaceae). PLoS One. doi: 10.1371/journal.pone.0142734.
Interpretive Summary: Liberibacter is the bacterial pathogen associated with zebra chip disease of potato, and is transmitted by the potato psyllid. Managing zebra chip disease is difficult in part because our knowledge of which weedy hosts are sources of Liberibacter infected psyllids entering fields of potato is limited. Certain plants including sweet potato and field bindweed are suitable hosts for the psyllid, but are not thought to be hosts for Liberibacter. USDA-ARS researchers in Wapato, WA, along with researchers at Heritage University in Toppenish, WA, determined that uninfected potato psyllids were capable of acquiring Liberibacter from sweet potato and field bindweed, but only if Liberibacter-infected psyllids were present on the plants at the same time as the uninfected psyllids. These results indicate that field bindweed and related weeds may be at least minor sources of Liberibacter-infected psyllids entering fields of potato, and that managing these weeds may reduce the spread of zebra chip disease.
Technical Abstract: “Candidatus Liberibacter solanacearum” (Proteobacteria) is an important pathogen of solanaceous crops (Solanales: Solanaceae) in North America and New Zealand, and is the putative causal agent of zebra chip disease of potato. This phloem-limited pathogen is transmitted to potato and other Solanaceous plants by the potato psyllid, Bactericera cockerelli (Hemiptera: Triozidae). While some plants in the Convolvulaceae (Order: Solanales) are also known hosts for B. cockerelli, previous efforts to detect Liberibacter in Convolvulaceae have been unsuccessful. Moreover, studies to determine whether Liberibacter can be acquired by psyllids from these plants are lacking. The goal of our study was to determine whether horizontal transmission of Liberibacter occurs among psyllids on two species of Convolvulaceae, sweet potato (Ipomoea batatas) and field bindweed (Convolvulus arvensis). Results indicated that uninfected psyllids acquired Liberibacter from both I. batatas and C. arvensis if infected psyllids were present on plants concurrently with the uninfected psyllids. Uninfected psyllids did not acquire Liberibacter from plants if the infected psyllids were removed from the plants before the uninfected psyllids were allowed access. In contrast with previous reports, PCR detected the presence of Liberibacter DNA in some plants, but visible amplicons were faint and did not correspond with acquisition of the pathogen by uninfected psyllids. None of the plants exhibited disease symptoms. Results indicate that horizontal transmission of Liberibacter among psyllids can occur on Convolvulaceae, and that the association between Liberibacter and Convolvulaceae merits additional attention.