The Weed Link in Zebra Chip Epidemiology: Suitability of Non-crop Solanaceae and Convolvulaceae to Potato Psyllid and “Candidatus Liberibacter Solanacearum”

Abstract

Potato psyllid (Bactericera cockerelli) is a vector of “Candidatus Liberibacter solanacearum”, the pathogen associated with potato zebra chip disease. While the psyllid apparently colonizes potato from non-crop Solanaceae or Convolvulaceae, the identity of these weed sources is uncertain. We examined susceptibility of ten non-crop species (one Convolvulaceae and nine Solanaceae) to potato psyllid and Liberibacter, with an emphasis on psyllid populations (northwestern and western haplotypes) and plant species that are present in the Pacific Northwest. Psyllids of the western haplotype survived and developed on all plant species, while psyllids of the northwestern haplotype survived on all species except Solanum physalipholium. All species except Lycium barbarum and Convolvulus arvensis were susceptible to Liberibacter. Results of our study provide the most extensive examination of plant suitability to potato psyllid and Liberibacter and will lead to improved capabilities of predicting which potato fields are at risk to arrival of infective psyllids.