Stability and Variability of Chromosome Numbers in the Genus Schoenoplectus (Cyperaceae). I. S. gemmifer, S. mucronatus var. mucronatus and S. triangulatus
2004 年 69 巻 1 号 p. 75-83
詳細
2004 年 69 巻 1 号 p. 75-83
The chromosomes of the new species Schoenoplectus gemmifer and the allied S. mucronatus var. mucronatus and S. triangulatus were studied in culm-apex cells and root-tip cells. The mitotic metaphase chromosomes were small and dot-like. The chromosome number in culm-apex cells was stable and was observed to be 2n=74 in S. gemmifer, 2n=38 in S. mucronatus, and 2n=42 in S. triangulatus, respectively. Thus, it was confirmed that the new species S. gemmifer was cytologically different from both S. mucronatus and S. triangulatus. Inter- and intra-individual variations in chromosome number, mixoploidy and aneuploidy, were found in the root-tip cells of the three species. Chromosome number (2n) varied from 68 to 74 in S. gemmifer, 2n=32 to 39 in S. mucronatus and 2n=37 to 44 in S. triangulatus, respectively. This phenomenon is very rare and this is the first report in the genus Schoenoplectus.
