Oral Presentation Science Protecting Plant Health 2017

Diversity of Brevipalpus-transmitted plant viruses   (4167)

Elliot W. Kitajima 1 , Juliana J Freitas-Astúa 2 , Pedro Luiz PL Ramos-González 2 , Ralf R Dietzgen 3
  1. Universidade de São Paulo, Piracicaba, SP, Brazil
  2. Fitopatologia Bioquímica, Instituto Biológico, São Paulo, SP, Brazil
  3. QAAFI, University of Queensland, St. Lucia, Queensland, Australia

Only a handful of Brevipalpus (Acari, Tenuipalpidae)-transmitted viruses (BTV) were known until the turn of  the 20th century, but since then up to 40 new cases have been reported. Molecular characterization accompanied by biological and morphological data significantly increased our knowledge on BTV. There are basically two types of BTV: (1) cytoplasmic, bacilliform particles inducing a cytoplasmic viroplasm, with a genome of (+) ssRNA either bipartite (Cilevirus) or tripartite (Higrevirus), represented respectively by Citrus leprosis C cilevirus  and Hibiscus green spot  2 higrevirus; (2) nuclear, rodlike virions causing an intranuclear viroplasm, genome of (-) ssRNA, bipartite (Dichorhavirus), with Orchid fleck dichorhavirus  as the type species.  


In the last few years several new putative members were added to the genus Cilevirus: Citrus leposis virus C2; Passion fruit green spot virus , Ligustrum leprosis virus and Solanum violaefolium ringspot virus. Similarly, in addition to the two accepted species of genus Dichorhavirus, Orchid fleck dichorhavirus and Coffee ringspot dichorhavirus, putative members are Clerodendrum chlorotic spot virus, Cestrum ringspot virus, a recently characterized Citrus leprosis virus N and Citrus chlorotic spot virus from Brazil, among others. Overall, the new viruses show 50-70% nucleotide sequence identity with their cognates in the two genera. Nuclear type of citrus leprosis from Mexico and Colombia was demonstrated to be caused by citrus isolate of orchid fleck virus (OFV).


So far, except for OFV which has a worldwide distribution, and HGRSV-2 found in Hawaii, all reported cases of BTV occurred in the Americas, but BTV most likely will also be present in other parts of the globe.