Differential acquisition of Brazilian maize bushy stunt phytoplasma strains by the corn leafhopper vector Dalbulus maidis

AbstractMaize bushy stunt phytoplasma is a pathogenic bacterium transmitted by the corn leafhopper, Dalbulus maidis (Hemiptera: Cicadellidae), in a persistent-propagative manner. This phytoplasma is a key component of a reemerging disease complex that poses a major threat to maize production across the American continent. While some studies have reported genetic variation among maize bushy stunt phytoplasma strains, it remains unclear whether these variations influence the transmission efficiency by D. maidis. Here, it was assessed the efficiency of acquisition by its insect vector. Six Brazilian strains were obtained from field samples and maintained in greenhouse through serial transfer using D. maidis from a healthy colony. Acquisition efficiency was evaluated by exposing groups of 100 third-instar D. maidis nymphs to maize bushy stunt phytoplasma-infected plants. The findings indicate that these Brazilian strains exhibit differential acquisition efficiencies. A higher likelihood of acquisition may be linked to host manipulation strategies that enhance pathogen persistence and dissemination to new niches.