Differentiation between diploid and tetraploid Centaurea phrygia: mating barriers, morphology and geographic distribution

• Main Authors: Koutecký, P., Štěpánek, J. (Jan), Baďurová, T.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2012
• Subjects: geographic distribution; polyploidy; reproductive isolation; Centaurea phrygia
• Online Access: http://hdl.handle.net/11104/0007465

Karyological variation, reproductive isolation, morphological differentiation and geographic distribution of the cytotypes of Centaurea phrygia were investigated in Central Europe. Occurrence of two dominant cytotypes, diploid (2n = 22) and tetraploid (2n = 44), was confirmed and additionally triploid, pentaploid and hexaploid ploidy levels identified using flow cytometry. Allozyme variation as well as morphological and genome size data suggest an autopolyploid origin of the tetraploids. Crossing experiments and flow cytometric screening of mixed populations revealed strong reproductive isolation of the cytotypes. Multivariate morphometric analysis revealed significant differentiation between the cytotypes in several morphological characters. The name Centaurea phrygia is applied to the diploids and the name C. erdneri belongs to the tetraploids; nomenclature of hybrids with C. jacea is also resolved.