Karyotype Variations of Tricyrtis hirta Hook. (Liliaceae)

Abstract

Karyotypes of Tricyrtis hirta, endemic to Japan, are highly variable. it has chromosome numbers of 2n=24, 25 and 26. The plants with 2n=24 were restricted in the Peninsulas of Boso, Izu and Kii, and those with 2n=25 were only found in Boso and Izu. The karyotype of 2n=24 was probably derived from that of 2n=26 through Robertsonian fusion in two pairs of the telocentric chromosomes, and the plants with 2n=25 are possibly hybrids between 2n=24 and 36. The morphology of the chromosomes other than the telocentrics or fused ones (the large metacentrics) is various, but there are apparently some geographical similarities, and six karyotypes can be distinguished. The karyotypes in most populations of Kyushu and Shikoku show high asymmetry. On the other hand, the populations in the Kanto and Chubu Districts and in the Inugatake population of Kyushu have rather symmetric karyotypes. These karyotypes may correspond to some morphological features of the plants.