KARYOTYPE ANALYSIS IN CYMNASTER

Abstract

1. The present investigation is concerned with a detailed account of chromosome morphology in the Genus Gymnaster, a member of the Family Compositae.
2. The karyotype of the Section Homolepis differs sharply from that of the Section Crassifolium.
3. The close resemblance of the karyotypes of G. pygmaeus to those of G. Savatieri supports the phylogenetic relationships of the two species.
4. Two triploids and a tetraploid of Gymnaster studied are, karyotypically, all autopolyploids.
5. The chromosome numbers and the karyotype formulas are as follows; Sect. Homolepis
G. Pygmaeus Kitamura 2x
K(2n)=18=2^csA^sm+2B₁^sm+2B₂^m+2C^sm+4D₁^sm+2D₂^m+4E^sm
G. Savatieri Kitamura 2x
K(2n)=18=2^csA^sm+2B₁^sm+4B₂^sm+4C₁^sm+2C₂^m+2D^sm+2E^sm
G. Savatieri Kitamura 3x
K(2n)=27=3^csA^sm+3B₁^sm+6B₂^sm+6C₁^sm+3C₂^m+3D^sm+3E^sm
G. Savatieri Kitamura 4x
K(2n)=36=4^csA^sm+4B₁^sm+8B₂^sm+8C₁^sm+4G₂^m+4D^sm+4E^sm
G. Savatieri Kitamura (Aster Savatieri var. hortorum Makino) 2x
K(2n)=18=2^csA^sm+2B₁^sm+4B₂^sm+4C₁₄₇₂^sm+2C₂^m+2D^sm+2E^sm
G. Savatieri Kitamura (A. Savatzer var. hortorum Makino) 3x
K(2n)=27=3^csA^sm+3B₁^sm+6B₂^sm+6C₁^sm+3G₂^m+3D^sm+3E^sm
Sect. Crassifolium
G. koraiensis Kitamura
K(2n)=144=8A₁^st+6A₂^sm+14B₁^sm+12B₂^m+6C₁^st+72C₂^sm+6D₁^st+14D₂^m+6E^sm