Genetic Variability of Haplaxius crudus, Based on the 5′ Region of the Cytochrome c Oxidase Subunit I Gene, Sheds Light on Epidemiology of Palm Lethal Decline Phytoplasmas

Abstract

Haplaxius crudus is an economically important species of cixiid planthopper that is widespread and abundant throughout the Caribbean basin. It is the vector of lethal yellowing and putative vector of lethal bronzing, both phytoplasma diseases of palm that cause death in Florida and the Caribbean. The primary objective of this study was to evaluate the genetic diversity of H. crudus in Florida to determine whether divergent populations existed. The 5′ region of the cytochrome c oxidase subunit I gene was used as the molecular marker. DNA sequences were obtained from 236 specimens collected throughout Florida, United States as well as populations from the southeastern United States. Populations from Costa Rica, Colombia, and Jamaica were included to compare differences between isolated populations. In Florida, four haplotypes were discovered, with 97% of individuals belonging to a single haplotype, two smaller haplotypes comprising six and four individuals, and a single haplotype comprising one individual. Populations from Texas and Mississippi represented distinct haplotypes whereas populations from Georgia and South Carolina were identical to the predominant haplotype in Florida. Populations from Costa Rica and Colombia were highly divergent whereas the population from Jamaica was 100% identical to the predominant population in Florida. These findings highlight measurable levels of genetic variability of H. crudus in Florida, and the similarity to populations from Jamaica highlight the need for more robust sampling throughout the Caribbean to better understand movement and invasion potential of this species. [Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .