Karyotypic analysis of different populations of Carthamus tinctorius Linnaeus (Asteraceae)

Somatic chromosomes of Carthamus tinctorius L. were analysed. A karyotype formula for each studied population was formulated. Although all samples have 2n = 24, they could be differentiated by their karyotype formula and quantitative parameters of the karyotypes. The chromosomes were assorted into different categories on the basis of arms ratio following Levan et al. (1964). These were further subdivided into different types, on the basis of total length of the chromosomes. Based on an evolutionary point of view, variation in total chromosome length without major changes in the karyotype formula suggests that changes in the amounts of genomic DNA are proportional to the relative length of an each chromosome arm. All samples possessed symmetrical or slightly asymmetrical karyotype. The samples belonging to the same species were showing intra-specific or inter-specific chromosome polymorphism. This finding may provide useful information for Carthamus evolutionary, genetic, and breeding studies.