Year: 2025
Type: article
Abstract: The family Schisandraceae comprises approximately 23 species across three genera worldwide. On the Korean Peninsula, the two species of Schisandra, S. chinensis, S. repanda, and the species of Kadsura japonica occur. Although many pharmacological studies have been conducted on S. chinensis, cytological studies remain limited. Thus, we conducted a cytogenetic study to examine the chromosome morphology and the locations of rDNA signals. Chromosome slides were prepared from the root tips of these three species to determine chromosome numbers. Additionally, fluorescence in situ hybridization was performed using 5S rDNA and 45S rDNA. All three species had a chromosome number of 2n=28. Each species exhibited one pair of the 5S rDNA and one pair of 45S rDNA signals. Unlike S. chinensis and S. repanda, K. japonica possessed a pair of satellite chromosomes. The 5S rDNA signal was consistently observed on chromosome 5 in all three species. In contrast, the 45S rDNA signal was located on chromosome 7 in S. chinensis, but on chromosome 12 in S. repanda and K. japonica. The presence of the SAT chromosome can distinguish Kadsura from Schisandra. Furthermore, the position of the 45S rDNA signal could be used to differentiate between S. chinensis and S. repanda. The total chromosome number (2n=28) and the presence of a 5S rDNA signal on chromosome 5 are thus considered symplesiomorphies in the chromosomal evolution of the Schisandraceae. The SAT chromosome of K. japonica is considered autapomorphic. In addition, the differing locations of 45S rDNA signals between the two Schisandra species suggest that Kadsura may be more primitive. Among Schisandra, species with a 45S rDNA signal on chromosome 7 are considered advanced. Thus, it can be inferred that chromosomes evolved to become shorter in length and lost the SAT chromosomes in Schisandraceae. Our study contributes to a better understanding of the evolutionary relationships within this family.
Source: CYTOLOGIA
Authors: Se-Moon Ahn, Hye-Rin Kim, Kweon Heo
Institution: Kangwon National University
Language: English
Subfield: Plant Science
Domain: Life Sciences
Open Access status: diamond
OpenAlex ID: W4414461176