VARIATION AND EVOLUTION OF KARYOTYPE CHARACTERS IN PALM SUBFAMILY CORYPHOIDEAE SL

Karyological data are presented for 13 genera of palm subfamily Coryph oideae s.l. Chromosome numbers of 4 species and of genus Guihaia (G. a rgyrata, 2n = 36) are new. Apart from the prevailing chromosome number of 2n = 36, subfam. Coryphoideae s.l. shows extreme heterogeneity wit h respect to chromosome size and morphology, organization of constitut ive heterochromatin (C-banding, fluorochrome staining), interphase nuc leus structures and prophase condensation patterns. Five karyologicall y differing groups of genera can be distinguished (Coccothrinax-group, Guihaia, Livistona-group incl. Sabal, Phoenix, and Bismarckia). Chrom osome evolution probably has gone from medium sized to very small chro mosomes with an average length of less than 1.5 mum; hc-distribution f rom evenly distributed throughout the karyotype to accumulated in few chromosomes; from simple banding patterns to complicated ones (hc-elab oration). Karyotypes with chromosomes of continuously decreasing size, similar morphology, and uniform prophase condensation probably gave r ise to almost bimodal karyotypes with non-uniform, heteropycnotic chro mosomal structures. Changes in the organization of interphase nuclei a re corresponding. Karyotype differentiation is compared to major evolu tionary events in floral and vegetative morphology of subfam. Coryphoi deae s.l. Karyologically, genera Phoenix and Bismarckia are isolated a nd the relations to the remaining part of the subfamily are not clear.