Karyomorphology of twelve species in Euphorbia genus from Turkey

Abstract

Karyotypes in 12 taxa of Euphorbia were studied karyomorphologically. The karyotypes of Euphorbia cheiradenia, E. pannonica, E. pestalozzae, E. petrophila, E. pisidica, E. thessala and E. yildirimli are described for the first time. Karyological analyses indicate relationships among the species with respect to their asymmetry indices. Most of the investigated taxa are diploid with 2n = 2x = 18 chromosomes. E. macroclada and E. smirnovii showed tetraploid cytotypes 2n = 4x = 36. All karyotypes are symmetrical, consisting of metacentric and submetacentric chromosomes. The chromosomes range in size from 0.79 µm to 2.20 µm. The total haploid chromosome length (THL) varies from 8.75 μm (E. terracina) to 16.78 μm (E. petrophila). PCoA (Principal Coordinate Analysis) with five uncorrelated parameters was performed to determine the karyological relationships among the taxa.

Keywords

• Chromosome number
• karyotype asymmetry
• Pithyusa
• Esula
• tetraploid
• karyosystematic