Addressing emerging plant viruses in Florida

Abstract

Vegetable and ornamental crops produced in the subtropical/tropical state of Florida have experienced a number of emerging viruses over the last 2 decades. Most of these viruses belong to one of the following plant virus families: Betaflexiviridae, Bunyaviridae, Closteroviridae, Geminiviridae or Potyviridae. Emerging viruses have appeared in Florida through different routes or mechanisms, and their effects on hosts have also varied. The viruses that have caused the biggest concerns are those transmitted by either a single species of whitefly (Bemisia tabaci MEAM1) or various species of thrips. The response to these emerging plants viruses has varied with the type of virus. These range from the standard responses (development of virus-specific assays, surveys, testing cultivar susceptibility, and identification of host range, development or modification of insect management guidelines) to metagenomic studies to identify viruses before they emerge in epidemics. The metagenomic approach is the newest and has allowed the identification of plant viruses before they became problematic. Metagenomes can be constructed from the plants in question, or from the vectors. Metagenomes from vectors are particularly helpful when the vector is both polyphagous and highly mobile. Specific emerging viruses, their impacts and responses will be discussed.