A karyotype analysis of five wild rose species (Rosa helenae, R. mulliganii, R. multiflora, R. rubus, and R. solieana) was performed using bicolor fluorescence in situ hybridization (FISH). All five species were found to be diploid (2n = 2x = 14). The chromosome length in the metaphase stage ranged from 1.29 to 2.05 μm in R. helenae, 3.32 to 6.82 μm in R. mulliganii, 1.58 to 2.24 μm in R. multiflora, 2.05 to 3.46 μm in R. rubus, and 1.62 to 2.46 μm in R. solieana. The chromosomes were either metacentric or submetacentric, with no subtelocentric or telocentric chromosomes being observed. Each p air of 5 S and 4 5S rDNA sites was detected at the proximal region of the long arm and the terminal region of the short arm of chromosome #7, respectively.

Dual-color fluorescence in situ hybridization karyotype analysis was created using repetitive sequences including two types of rDNA repeats (45S and 5S rDNAs) and Arabidopsis-type telomere sequence repeats. The somatic metaphase cells of Carthamus tinctorius were observed as diploids (2n=2x=24). A symmetrical or slightly asymmetrical karyotype with seven pairs of metacentric and five pairs of submetacentric chromosomes was observed. The lengths of the somatic metaphase chromosomes ranged from 4.18 to 6.53 ㎛, with a total length of 60.71 ㎛. One locus of 45S rDNA was located on the pericentromeric regions of three pairs of chromosomes and the other pair was situated on the terminal regions of the short arms of a single pair of chromosomes. One locus of 5S rDNA was detected on the interstitial regions of the short arms of two pairs of chromosomes. Arabidopsis-type telomeric repeats were detected on the terminal regions of all pairs of chromosomes. Co-localization of loci between telomeric repeats and 45S rDNA was observed in a single pair of chromosomes. The results provide additional information for the existing physical mapping project of C. tinctorius and will also serve as a benchmark to a more intricate cytogenetic investigation of C. tinctorius and its related species.

In the genus Chrysanthemum, repetitive DNA sequences, the dominant part of a genome, are still to be elucidated. To explore the matter, the present study applied fluorescent in situ hybridization (FISH) to the mitotic metaphase chromosome of Chrysanthemum boreale with C0t DNA as probes. Based on DNA re-assotiation kinetics, three kinds of C0t DNA exhibiting different degrees of repetitive nature were fractionated and used as FISH probes to map the repetitive sequences. Signals from all C0t DNAs were successfully observed but their coverage on the chromosomes was different among C0t-1, C0t-10, and C0t-100. C0t-1 FISH signals resulted to have its intensity on the telomeric region and were also dispersed on both chromosome arms except for some distal regions. In C0t-10, signals were observed in all parts of the chromosome with greater intensity around pericentromeric regions. FISH with C0t-100 DNA was observed in bright signals all over the chromosome. Signals of C0t FISH found in this study covered the regions where ribosomal DNAs and telomeric repeats of C. boreale have been distributed (previous report), thus signifying their repetitive attributes. The present results could enhance the efficiency of studying genomes, chromosomes and repetitive sequences of C. boreale and subsequently hasten the realization of the genetic scheme of Chrysanthemum.