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.

The objective of this study was to develop PCR primers that are specific for Streptococcus sanguinis, Streptococcus parasanguinis, and Streptococcus gordonii. We designed the S. sanguinis-, S. parasanguinis-, and S. gordonii- specific primers, Ssa21-F3/Ssa21-R2, Spa17-F/Spa17-R, and Sgo41-F1/Sgo41-R1 respectively, based on the nucleotide sequences of the Ssa21, Spa17, and Sgo41 DNA probes that were screened using inverted dot blot hybridization (IDBH). The species-specificity of these primers was as- sessed against 43 strains of mitis group streptococci, in- cluding clinical strains of S. sanguinis, S. parasanguinis, and S. gordonii. The resulting PCR data revealed that species-specific amplicons had been obtained from all strains of the target species tested, and that none of these amp- licons occurred in any other strains from other species. These results suggest that the Ssa21-F3/Ssa21-R2, Spa17- F/Spa17-R, and Sgo41-F1/Sgo41-R1 primers may be useful in detecting S. sanguinis, S. parasanguinis, and S. gordonii at the species level, 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.