RESUMEN
Seven apiculate yeast strains that were isolated from the flowers of Syphocampylus corymbiferus Pohl in Brazil are genetically, morphologically and phenotypically distinct from recognized species of the genera Hanseniaspora and Kloeckera. Genetic discontinuities between the novel strains and their closest relatives were found using a networking approach based on the concatenated sequences of the rRNA gene (internal transcribed spacer and D1/D2 of the LSU), and the protein-coding genes for actin and translation elongation factor-1α. Phylogenetic analysis based on the rRNA and the actin gene placed the novel species represented by the strains in close relationship to Hanseniaspora meyeri and Hanseniaspora clermontiae. PCR fingerprinting with microsatellite primers confirmed the genetic heterogeneity of the novel species. The name Hanseniaspora nectarophila sp. nov. is proposed, with UFMG POG a.1(T) (â= ZIM 2311(T)â = CBS 13383(T)) as the type strain; MycoBank no. MB807210. As the current description of the genus does not allow the presence of multilateral budding, an emended diagnosis of the genus Hanseniaspora Zikes is proposed.
Asunto(s)
Campanulaceae/microbiología , Flores/microbiología , Hanseniaspora/clasificación , Filogenia , Actinas/genética , Brasil , ADN de Hongos/genética , ADN Espaciador Ribosómico/genética , Genes Fúngicos , Hanseniaspora/genética , Hanseniaspora/aislamiento & purificación , Datos de Secuencia Molecular , Técnicas de Tipificación Micológica , Factor 1 de Elongación Peptídica/genética , Análisis de Secuencia de ADNRESUMEN
Two protein-coding genes, actin and translation elongation factor-1alpha (EF-1alpha), as well as two ribosomal gene regions, D1/D2 domains of the large subunit and both internal transcribed spacers including the 5.8S gene region, were evaluated regarding their usefulness for reconstruction of phylogenetic relationships in the Hanseniaspora-Kloeckera species group. This included analyses of sequence divergence values, heterogeneity of evolutionary rates and the reliability of the inferred trees. Both protein-coding genes showed greater capacities to resolve at the strain level and between the closely related species of Hanseniaspora-Kloeckera, compared with the ribosomal gene regions. However, to obtain a fully resolved and reliable phylogenetic tree that reflected the biological relationships it was necessary to combine three congruent sequence datasets. The novel species Hanseniaspora pseudoguilliermondii sp. nov. (type strain CBS 8772T) is described as a result of the application of various molecular approaches to delimit species. Furthermore, incongruent gene genealogies of genetically divergent strains of Hanseniaspora occidentalis, as determined by amplified fragment length polymorphism analysis and DNA-DNA reassociation measurements, indicated the presence of two novel varieties, H. occidentalis var. occidentalis (type strain CBS 2592T) and H. occidentalis var. citrica var. nov. (type strain CBS 6783T), which could be distinguished by habitat preference.