Two Separate Introductions of Asian Citrus Psyllid Populations Found in the American Continents

Abstract

Se realizó un estudio filogeográfico a partir del gen COI con 22 poblaciones de Diaphorina citri Kuwayama recolectadas en las Américas y una en el Pacífico.Se analizaron poblaciones de cuatro países de América del Sur, de cuatro países de América del Norte y una de Hawái. Se identificaron veintitrés haplotipos y se dividieron en dos grupos: hp1-8 se identificaron en América del Sur (grupo 1) y hp9-23 se identificaron en América del Norte y Hawái (grupo 2). Los datos sugieren que ocurrieron dos introducciones separadas o eventos de colonización de D. citri en las Américas, una en América del Sur y otra en América del Norte. Además, América del Norte y Hawái parecen compartir una fuente similar de invasión. Estos datos pueden ser importantes para el desarrollo de programas de control biológico contra D. citri en las Américas.

A phylogeographic analysis inferred from the partial mitochondrial cytochrome oxidase subunit I gene (433 bp) was performed with 22 populations of Diaphorina citri Kuwayama collected in the Americas and one in the Pacific. Eight populations from four countries in South America, 14 from four countries in North America, and one from Hawaii were analyzed. Twenty-three haplotypes (hp) were identified and they fell into two groups: hp1–8 were identified in South America (group 1) and hp9–23 were identified in North America and Hawaii (group 2). Hp1 and nine were present in the highest frequencies within each population and within their group, 81 and 85% for group 1 and group 2, respectively. A diagnostic nucleotide at position 48 was identified that allowed for the discrimination of the two groups; in addition, no haplotypes were shared between the two groups. An analysis of molecular variance uncovered significant genetic structure (φCT = 0.733; P < 0.001) between the two groups of the Americas. Two haplotype networks (ParsimonySplits and Statistical Parsimony) discriminated the two groups and both networks identified hp1 and nine as the predicted ancestral or founding haplotypes within their respective group. The data suggest that two separate introductions or founding events of D. citri occurred in the Americas, one in South America and one in North America. Furthermore, North America and Hawaii appear to share a similar source of invasion. These data may be important to the development of biological control programs against D. citri in the Americas.