Autor(es):
Pereira, Filipe 
; Moreira, Claudia ; Fonseca, Luis ; Asch, Barbara ; Mota, Manuel ; Abrantes, Isabel ; Amorim, António
Data: 2013
Identificador Persistente: http://hdl.handle.net/10174/10110
Origem: Repositório Científico da Universidade de Évora
Assunto(s): Bursaphelenchus xylophilus; Bursaphelenchus mucronatus
Descrição
The pinewood nematode, Bursaphelenchus xylophilus, is one of the greatest threats to coniferous forests worldwide, causing
severe ecological damage and economic loss. The biology of B. xylophilus is similar to that of its closest relative, B.
mucronatus, as both species share food resources and insect vectors, and have very similar morphological characteristics,
although little pathogenicity to conifers has been associated with B. mucronatus. Using both nuclear and mitochondrial
DNA markers, we show that B. xylophilus and B. mucronatus form distinct phylogenetic groups with contrasting
phylogeographic patterns. B. xylophilus presents lower levels of intraspecific diversity than B. mucronatus, as expected for a
species that evolved relatively recently through geographical or reproductive isolation. Genetic diversity was particularly
low in recently colonised areas, such as in southwestern Europe. By contrast, B. mucronatus displays high levels of genetic
diversity and two well-differentiated clades in both mitochondrial and nuclear DNA phylogenies. The lack of correlation
between genetic and geographic distances in B. mucronatus suggests intense gene flow among distant regions, a
phenomenon that may have remained unnoticed due to the reduced pathogenicity of the species. Overall, our findings
suggest that B. xylophilus and B. mucronatus have different demographic histories despite their morphological resemblance
and ecological overlap. These results suggest that Bursaphelenchus species are a valuable model for understanding the
dispersion of invasive species and the risks posed to native biodiversity and ecosystems.
