Karyotype analysis in some Chara species (Charales, Charophyceae) in Iran

Abstract

Karyological characteristics were determined in 36 populations of eight Chara species and varieties distributed in Iran. The karyotype asymmetry/symmetry were evaluated using CVCL (coefficient of variation of chromosome length), CVCI (heterogeneity of the centromeric index) and MCA (mean centromeric asymmetry). Results obtained from the current study revealed that there are two different ploidy levels (n = 14 and n = 28) among the investigated taxa. All eight species and varieties had metacentric (M & m), sub-metacentric (Sm) and sub-telocentric (St) chromosomes, but the majority of taxa showed a dominance of metacentric and sub-metacentric chromosomes. In general, the karyotypes within the genus Chara were symmetrical, but the studied species differed significantly in quantitative features of karyotype and revealed the occurrence of qualitative changes during the species diversification. The present study reveals that karyological features may be of great help in Chara species delimitations.