Chrysanthemum is one of the most popular and economically important ornamental plants due to its huge diversity in growing habits, wide range of colors, and different patterns of flower. In the present study, we conducted the karyotype analysis in four naturally occurring genotypes of Chrysanthemum boreale. Karyotype studies based on the fluorescence in situ hybridization (FISH) using 5S and 45S rDNAs. Four chrysanthemum genoteyps showed an aneuploid chromosome number of 2n=18+2 (111016 and 111021) or a diploid of 2n=18 (121001 and 121002). All the genoteyps had the same karyotype formula of 14 metacentrics and 4 submetacentrics. In 111016, the chromosome length during somatic metaphase ranged from 3.11 ± 0.26 μm (shortest) to 3.94 ± 0.20 μm (longest), with a total length of 32.94 μm. The chromosome length at the mitotic metaphase ranged from 3.11 to 6.46 μm, with a total length of 32.94 μm in 111016 and 51.05, 32.81, and 46.00 μm in 111021, 121001, and 121002, respectively. The 5S rDNA and 45S rDNA signals recorded different in all four wildly grown genotypes of C. boreale. This information can be useful in cultivar improvement, as well as in elucidation of the evolution of the chrysanthemum.

Polyploidy analysis being one of the important mechanisms to study the genetic resources and plant diversity which plays significant role in crop evolution, breeding programs, and crop improvement was conducted in this study. The root tips of nine Cymbidium genotypes were used as materials to determine their chromosome number and flow cytometric analysis of chromosomal ploidies. The chromosome number (2n=40) has been observed in all the nine genotypes. Results showed that among nine cymbidium genotypes, six were tetraploid (2n=4x=80), two diploid (2n=2x=40), and one triploid (2n=3x=60). This study provides useful chromosome landmarks and evidence about genome evolution, heteromorphic chromosomes based heterozygosity, basic chromosome number and ploidy level in the genus Cymbidium. These results can be used as theoretical base line for crossbreeding in the genus Cymbidium.

Conventional staining and fluorescence in situ hybridization (FISH) karyotypes of the non-genetically modified (GM) parental rice line, 'Nakdong' (Oryza sativa L. japonica), and its four GM rice lines, LS28 (event LS30-32-20-1), Cry1Ac1 (event C7-1-9-1), and LS28 × Cry1Ac1 (events L/C1-1-3-1 and L/C1-3-1-1) were analyzed using 5S and 45S rDNAs as probes. Both parental and transgenic lines were diploids (2n=24) with one satellite chromosome pair. The lengths of the prometaphase chromosomes ranged from 1.50 to 6.30 μm. Four submetacentric and eight metacentric pairs comprised the karyotype of 'Nakdong' and its four GM lines. One pair of 5S rDNA signals was detected near the centromeric region of chromosome g in both the parental and transgenic lines. The 45S rDNA signals were detected on the secondary constrictions of the satellite chromosome pair in both the parental and transgenic lines. There was no significant difference in chromosome size, length, and composition between 'Nakdong' and its four GM lines. This research was conducted as a preliminary study for chromosomal detection of transgenes in GM rice lines and would be useful for their breeding programs.