Chromosome Studies in Chionographis (Liliaceae)

II. Morphological characteristics of the somatic chromosomes of four Japanese members

抄録

Four Japanese members of Chionographis were investigated karyologically. Both C. japonica and C. koidzumiana had 2n=24 chromosomes, while C. japonica var. kurohimensis and C. japonica var. hisauchiana had 2n=44 and 2n=42 chromosomes, respectively. In the interphase nuclei, many small heteropycnotic segments, the number of which surpassed frequently the somatic chromosome number of each species, were observed. The chromosomes at early prophase had also many small precociously condensed segments, showing the beaded configuration. The chromo-somes at metaphase lay flat on the equatorial plane, and had no particular structure suggesting the presence of a localized kinetochore. The sister chromatids at ana-phase underwent a parallel disjunction. These observations of the chromosomes at metaphase and anaphase have suggested that the somatic chromosomes of all the species studied are holokinetic (holocentric). Relationships between the species were also discussed briefly from a karyological standpoint.