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Molecular and morphometric analyses of Xiphidorus species (Nematoda: Longidoridae)

2004; Brill; Volume: 6; Issue: 5 Linguagem: Inglês

10.1163/1568541042843487

1568-5411

Brian Fenton, C. M. G. Oliveira, Aílton Rocha Monteiro, G. Malloch, Roy Neilson, Luiz Carlos Camargo Barbosa Ferraz,

Mollusks and Parasites Studies

Abstract Xiphidorus nematodes are indigenous to Latin America and have a restricted geographical distribution compared to Xiphinema. A principal component analysis (PCA) based on eight morphometric characters from 39 South American populations clearly separated populations previously identified as X. achalae, X. amazonensis, X. minor, X. saladillensis and X. uruguayensis and three undescribed Xiphidorus species. However, populations identified as X. balcarceanus, X. parthenus and X. yepesara did not form similar discrete groupings and exhibited either considerable morphological variability or were incorrectly identified. Maximum likelihood phylogenetic trees derived from both 18S rDNA and ITS-1 sequences discriminated six Xiphidorus species (X. balcarceanus, X. minor, X. parthenus, X. yepesara, and two undescribed Xiphidorus species) from Brazil. Also, restriction analysis of PCR products derived from the ITS-1 region using three restriction enzymes (Taq I, Rsa I and Hin f I) yielded repeatable patterns that clearly discriminated these six Xiphidorus species. Sequence divergence was noted between X. parthenus and X. yepesara. Our morphometric and molecular data suggests that X. parthenus and X. yepesara are distinct species contrary to their previous subspecific status.