Biosystematic studies on the genus Polygonatum(Liliaceae). I. Karyotype analysis of species indigenous to Japan and its adjacent regions.

Abstract

Thirteen species, including six varieties and one form, of the genus Polygonatum of Japan, Taiwan, and Cheju Island, Korea, were examined karyologically. Among the species with x=9, P. cryptanthum, P. involucratum and P. trichosanthum possessed 2n=18 chromosomes, while P. falcatum was 2n=18 and 2n=18+4B-8B. All four species possessed almost identical karyotypes. While, among the species with x=10, P. humile possessed 2n=20 chromosomes. Diploid (2n=20) and triploid (2n=30) plants were found for P. lasianthum and P. odoratum. Those with 2n=30 chromosomes are considered to be autotriploid. Karyotypes of P. humile and P. lasianthum resembled each other, but were quite different from that of P. odoratum. Among the species with x=11, P. inflatum and P. cyrtonema possessed 2n=22, and P. macranthum was 2n=22, 2n=22+1B and 2n=22+3B. Karyotypes of P. inflatum and P. macranthum resembled each other, but were quite different from that of P. cyrtonema. Karyotypes of P. desoulavyi var. azegamii with 2n=18, P. domonense with 2n=19 and P. miserum with 2n=19 were quite asymmetric, thus not forming homologous pairs. The origin of such heterogenous karyotypes is not clear at present. Based on these results, the status of each taxon and previous taxonomic treatments were discussed.