Cytogenetic Behavior, Chromosomal Differentiations, and Geographic Distribution in Lilium lancifolium (Liliaceae)

Abstract

Abstract Lilium lancifolium Thunb, is the only polyploid species complex consisting of 2x (2n=24) and 3x (2n=36) forms in the genus, both of which are highly self‐sterile. They are cytologically differentiated into various nucleolar types by number and combination of four kinds of nucleolar chromosomes. The 3x form is widespread from the North‐East district of China to the Japanese Islands through the Korean Peninsula. However, the 2x form is localized and grows singly or together with the 3x form in the narrow zone from southern Korea to the Tsushima Islands, Japan. The 2x form reproduces by sexual as well as by asexual means, but a sterile 3x form has asexually persisted to the present. Generally speaking, the 3x form is the allotriploid which has originated from hybridization between a 2x form and a closely related species such as L. maximowiczii in the remote past. In the present study, another possibility for the presence of the autotriploid form is newly proposed based on its karyotype and geographic distribution.