title: Variability study of entomopathogenic nematode populations (Heterorhabditidae) from Argentina.
abstract: Entomopathogenic nematodes (EPN) belonging to the Heterorhabditidae family are lethal parasites of soil-dwelling insects. Two species were reported in Argentina: Heterorhabditis argentinensis and Heterorhabditis bacteriophora characterized mainly by morphometric features. In this work a comparative and phylogenetic study between five Heterorhabditis populations from Argentina was conducted to analyze the variability between strains and to evaluate the taxonomic position of Heterorhabditis argentinensis. The PCA analyses of morphometric characters separated the larger juvenile, female and male H. argentinensis from H. bacteriophora populations. The juvenile (IJs) stage provided the clearest separation of Heterorhabditis populations presenting the least variability between strains. The variable L and MBW were highly related to H. argentinensis IJs. Three groups were separated by this stage considering PC1 and PC2: one formed by H. bacteriophora OLI, RIV and RN strains, (isolates from Córdoba and Río Negro province), one for H. bacteriophora VELI strain (Buenos Aires province) and one for H. argentinensis (Santa Fe province). Heterorhabditis bacteriophora VELI and H. argentinensis isolated from regions with more rainfalls and humidity presented larger values for morphometric features. Molecular analyses showed the Argentinian populations (H. bacteriophora VELI strain and H. argentinensis), forming a same clade, with six other H. bacteriophora populations (not from Argentina) with a genetic similarity between them of 99%. Heterorhabditis argentinensis presented one unique nucleotide that was not present in any of the other species of the clade. Considering the results of this study H. argentinensis would be conspecific to H. bacteriophora, constituting a strain with a great morphometric variation where the host and climatic conditions could have influenced on the measurements.
authors: Consejo Nacional de Investigaciones Científicas y Técnicas - CONICET, Centro de Estudios Parasitológicos y de Vectores - CEPAVE, Facultad de Ciencias Naturales y Museo, Universidade Nacional de La Plata - UNLP, Calle 60 y 121, s/n, La Plata, Buenos Aires, Argentina.
authors: M F
authors: MF
authors: Achinelly
authors: Consejo Nacional de Investigaciones Científicas y Técnicas - CONICET, Centro de Estudios Parasitológicos y de Vectores - CEPAVE, Facultad de Ciencias Naturales y Museo, Universidade Nacional de La Plata - UNLP, Calle 60 y 121, s/n, La Plata, Buenos Aires, Argentina.
authors: D P
authors: DP
authors: Eliceche
authors: Laboratorio de Ingeniería Genética y Biología Celular y Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas - CONICET, Universidad Nacional de Quilmes - UNQ, Roque Sáenz Peña, 352, Bernal, Buenos Aires, Argentina.
authors: M N
authors: MN
authors: Belaich
authors: Laboratorio de Ingeniería Genética y Biología Celular y Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas - CONICET, Universidad Nacional de Quilmes - UNQ, Roque Sáenz Peña, 352, Bernal, Buenos Aires, Argentina.
authors: P D
authors: PD
authors: Ghiringhelli
mesh_terms: D000818:Animals; D001118:Argentina; D061046:Biological Control Agents; D018509:DNA, Helminth / Q000235:genetics; D005260:Female; D007313:Insecta / Q000254:growth & development / Q000469:parasitology; D007814:Larva / Q000254:growth & development / Q000469:parasitology; D008297:Male; D010802:Phylogeny; D017172:Rhabditoidea / Q000033:anatomy & histology* / Q000145:classification* / Q000235:genetics / Q000502:physiology
chemical_list: D061046:Biological Control Agents; D018509:DNA, Helminth