4.3. Karyotype Analysis

For each accession, well spread metaphase plates were selected for assessing the chromosome number and the presence of ITRs. Individuals showing ITRs were further analyzed and the number of sites and their location along the chromosome were recorded. The chromosome arm was divided into four domains of equal size according to [91], i.e., centromeric (c), proximal (p), interstitial-proximal (ip), and interstitial-terminal (it) and the ITR sites detected were mapped on these chromosomal regions. Since most karyotypes of Asteraceae show metacentric chromosomes a reliable distinction between both arms was usually not feasible. Accordingly, the locations of ITR sites on both chromosome arms were pooled. Chromosome measurements were made on digital images using the computer application MicroMeasure version 3.2 [92].

The overview of the phylogenetic relationships among tribes is based on [27]. The tree was redrawn using the iTOL application [93] and Inkscape software.