title: Karyotypic differences and evolutionary tendencies of some species from the subgenus Obliquodesmus Mlad. of genus Scenedesmus Meyen (Chlorophyta, Chlorococcales).
abstract: Karyotype structures of Scenedesmus acuminatus (Lagerch.) Chod. and Scenedesmus pectinatus Meyen are compared. The karyotype of S. acuminatus (n = 5) is described for the first time. It reveals four large metacentric and one large submetacentric chromosomes (4M + 1SM). The established karyotype differences have been helpful in clarifying the taxonomic position of these two species. The cytological analyses of other related clonal cultures suggest an evolutionary transition from S. pectinatus towards S. regularis through S. pectinatus f. regularis, which correlates with the morphological data about their variability. These results are discussed from the cytogenetic, morphological and evolutionary point of view. On the basis of the karyotypic analysis, it was confirmed that from a taxonomic point of view S. pectinatus, S. acuminatus and S. regularis are separate biological species.
authors.affiliation: Cell Biology Laboratory, Department of Developmental Biology, University of Plovdiv, 24 Tsar Assen St., 4000 Plovdiv, Bulgaria. balik@uni-plovdiv.bg
authors.forename: Balik
authors.initials: B
authors.lastname: Dzhambazov
authors.forename: Rumen
authors.initials: R
authors.lastname: Mladenov
authors.forename: Ivanka
authors.initials: I
authors.lastname: Teneva
authors.forename: Detelina
authors.initials: D
authors.lastname: Belkinova
mesh_terms: D005075:Biological Evolution; D007621:Karyotyping; D044444:Scenedesmus / Q000235:genetics*; D013045:Species Specificity