Morphology versus DNA barcoding: two sides of the same coin. A case study of Ceutorhynchus erysimi and C. contractus identification.
Genotyping of 2 well-known weevil species from the genus Ceutorhynchus (Coleoptera: Curculionidae) distributed in west Palearctic, C. erysimi and C. contractus, revealed phenotype versus genotype inconsistencies in a set of 56 specimens (25 C. erysimi and 31 C. contractus) collected from 25 locations in Serbia and Montenegro. An analysis of the mitochondrial cytochrome oxidase subunit I gene (COI), widely used as a barcoding region, and a nuclear gene, elongation factor-1α (EF-1α), revealed stable genetic divergence among these species. The average uncorrected pairwise distances for the COI and EF-1α genes were 3.8%, and 1.3%, respectively, indicating 2 genetically well-segregated species. However, the genetic data were not congruent with the phenotypic characteristics of the studied specimens. In the first place, C. erysimi genotypes were attached to specimens with phenotypic characteristics of C. contractus. Species-specific PCR-RFLP assays for the barcoding gene COI were applied for the molecular identification of 101 additional specimens of both morphospecies (33 C. erysimi and 68 C. contractus) and were found to confirm this incongruity. The discrepancy between the genetic and morphological data raises the question of the accuracy of using a barcoding approach, as it may result in misleading conclusions about the taxonomic position of the studied organism. Additionally, the typological species concept shows considerable weakness when genetic data are not supported with phenotypic characteristics as in case of asymmetric introgression, which may cause certain problems, especially in applied studies such as biological control programs in which the biological properties of the studied organisms are the main focus.
Faculty of Science, Institute of Biology and Ecology, University of Kragujevac, 34000, Kragujevac, Serbia.
Svetlana
S
Stepanović
Department of Plant Pests, Institute for Plant Protection and Environment, Banatska 33, 11080, Zemun, Serbia.
Andrea
A
Kosovac
Department of Plant Pests, Institute for Plant Protection and Environment, Banatska 33, 11080, Zemun, Serbia.
Oliver
O
Krstić
Department of Plant Pests, Institute for Plant Protection and Environment, Banatska 33, 11080, Zemun, Serbia.
Jelena
J
Jović
Department of Plant Pests, Institute for Plant Protection and Environment, Banatska 33, 11080, Zemun, Serbia.|CABI, 1 Rue des Grillons, 2800, Delémont, Switzerland.
Ivo
I
Toševski
D000818:Animals; D058893:DNA Barcoding, Taxonomic / Q000379:methods*; D004272:DNA, Mitochondrial / Q000235:genetics; D003576:Electron Transport Complex IV / Q000235:genetics; D005838:Genotype; D054548:Montenegro; D020648:Peptide Elongation Factor 1 / Q000235:genetics; D010641:Phenotype; D017422:Sequence Analysis, DNA; D055771:Serbia; D013045:Species Specificity; D048889:Weevils / Q000033:anatomy & histology / Q000145:classification* / Q000235:genetics*
D004272:DNA, Mitochondrial; D020648:Peptide Elongation Factor 1; D003576:Electron Transport Complex IV
Ceutorhynchus contractus; Ceutorhynchus erysimi; DNA barcoding; PCR-RFLP; molecular identification; morphology