Diploid and Tetraploid Cytotypes of Centaurea stoebe (Asteraceae) in Central Europe: Morphological Differentiation and Cytotype Distribution Patterns

Abstract

The taxomically critical species Centaurea stoebe is represented in Central Europe by a diploid (2n=18) and a tetraploid (2n=36) cytotype. Their morphological differentiation and taxonomic treatment is still controversial. Karyological (chromosome numbers and flow cytometric measurements) and multivariate morphometric analyses were used here to address cytotype distribution patterns and their morphological differentiation. Material from 38 localities (771 individuals) in Slovakia, Hungary and Austria, including type localities of the names traditionally applied to the different cytotypes, was sampled and evaluated using both morphometric and karyological approaches. The morphological tendency towards cytotype differentiation is evident only at a population level, and is blurred at the level of individual plants. Diploid populations prevail in the area studied, as well as throughout Europe; mixed-cytotype populations were also found. The present data, namely the weak morphological distinction, largely sympatric occurrence of the cytotypes, and the existence of mixed-cytotype populations, favour taxonomic treatment as a single species, without recognition of infraspecific units.

Morphological, Genome and Gene Expression Changes in Newly Induced Autopolyploid Chrysanthemum lavandulifolium (Fisch. ex Trautv.) Makino

“…Second division restitution (SDR) modes of 2 n gamete were formed in process of tetraploid. A few fraction of epistasis were transmitted from the diploid parent to the teraploid plant with SDR to restrict to pairs of loci [37,38,39], and morphological changing of tetraploid plants may be part of reason.…”

On the identity of aCentaureapopulation on Procida Island, Italy:Centaurea corensisrediscovered

“…In Italy, tetraploid species from the Centaurea group are mainly present around the northern Adriatic sea as Centaurea spinosociliata Seenus (Lovrić 1982;Marcucci et al 1999) and C. stoebe subsp. australis Pančić ex A. Kern (Greuter 2006(Greuter -2013Španiel et al 2008).…”

Phenomenon of Cytomixis and Intraspecific Polyploidy (2<i>x</i>, 4<i>x</i>) in <i>Spergularia diandra</i> (Guss.) Heldr. & Sart. in the Cold Desert Regions of Kinnaur District (Himachal Pradesh)

“…It is thus apparent that morphological characters in both the cytotypes of the species are directly correlated with the increase in ploidy level which has also been reported in Andropogon gerardii Vitman (Keeler and Davis 1999), Centaurea jacea L. (Hardy et al 2000), Parasenecio auriculata (DC.) J.R. Grant (Nakagawa 2006), Dactylis L. (Amirouche and Misset 2007), Centaurea phrygia L. (Koutecký 2007), Rorippa amphibia L. (Luttikhuizen et al 2007), Centaurea stoebe L. (Španiel et al 2008(Španiel et al , Mráz et al 2011 and Ranunculus hirtellus (Kumar and Singhal 2011). Pollen grains are of uniform size in the tetraploid cytotype whereas those of 2x cytotype are of 3 different sizes, large, medium (typical) and small sized.…”