CONICET | Buscador de Institutos y Recursos Humanos

According to traditional taxonomical criteria, the fertilization aperture in this genus Oedogonium has been classified into pore or circumcision type. To contribute with information useful to clarify the systematics of the Oedogoniales, we have studiesd the oogonial aperture in Oedogonium decipiens var. decipiens showing a circumcision in median position. The aperture mechanism and associated strucutres (line of weakness and thin layer) are similar to those previously described i O. cardiacum. The type and position of the aperture in mature oogonia was also studied in the other seven Oedogonium species. In all the analyzed species, the fertlization aperture occurs along the line of weakness, but they would differ only in the opening degree of this line. Therefore, the types of oogonial aperture would not be so different as to discriminate groups of species belonging to the genus Oedogonium, in agreement with a previous molecular phylogenetic study of this group of algae.