MOLECULAR BASED-PHYLOGENETIC RELATIONSHIPS IN THE SUPERFAMILY CRICONEMATOIDEA USING ITS1-rDNA [RELACIONES FILOGENETICAS MOLECULARES EN LA SUPERFAMILIA CRICONEMATOIDEA USANDO ITS1-RADN. ]

Abstract

Populations of nematodes of the superfamily Criconematoidea were obtained and identified morphologicallyfrom different geographical areas in the continental United States. This previous information was used to analyze theirphylogenetic relationship based on the first internal transcribed spacer ribosomal region. Phylogenetic analysis of theITS1-rDNA region showed monophyletic and paraphyletic groups in Criconematidae: A) species of Mesocriconemaand Criconemoides; and B) Bakernema, Criconema Hemicriconemoides and Xenocriconemella species. SubfamilyHemicycliophorinae, (Caloosia, Hemicaloosia and Hemicycliophora) and family Tylenchulidae (Paratylenchus andGracilacus) were not resolved because of the high variation of the marker Molecular phylogenetic analysis using theITS1-rDNA marker rejects the hypothesis of a common ancestor for criconematids with double sheath or cuticle amongothers characters. This molecular phylogenetic study showed that ITS1-rDNA sequences are too variable to studyphylogenetics of Criconematoidea. However, ITS1-rDNA is useful to identify and to characterize species within families.