Karyomorphology and Evolution in Some Hamamelidaceae and Platanaceae(Hamamelididae;Hamamelidales)

摘要: Karyomorphology in 14 species of 12 genera representing a variation Hamamelidaceae and one Platanaceae (Platanus only) is investigated an effort to contribute understanding chromosome evolution inter- intrafamilial relationships. All show similar features at resting stage prophase, excepting that stageRhodoleia shows the simple, rather than simple-complex, chromocenter type as other genera. At metaphase all Hamamelidaceae, like ‘lower’ Hamamelididae, have chromosomes with median centromeres (m-chromosomes), those submedian (sm-chromosomes) subterminal (or terminal) (st-t-chromosomes) different frequencies, although frequencies ofst-t-chromosomes are always less 33%. InPlatanus,m-chromosomes lacking insteadst-t-chromosomes predominant (86%), feature seemingly very specialized. We confirmedx=7 Platanaceae,x=12 Hamamelidoideae Rhodoleioideae, andx=8 Exbucklandioideae Altingioideae (Hamamelidaceae). An analysis morphology supports hypothesis thatx=12 former two subfamilies tetraploid origin fromx=6, triploid fromx=8. further give brief comments on suprageneric classification was recently proposed by Endress.