Abstract:

Abstract: Four Species of Hybrid F1 Generation between Cymbidium hybridiumand Chinese Cymbidiumare karyologically analyzed.Their karyotype formula and index of karyotypic asymmetry (As.k)are presented as follows:Cym.Lovely Valley‘Evergreen’×Cym. Longibracteatum,2n=3x=45m+15sm,As.k=59.75%;Cym.KLR565×Cym.sinense,2n=3x=42m+18sm，As.k=59.33℅;Cym.Summer Queen×Cym. Longibracteatum 2n=2x=30m+10sm,As.k=58.58℅;Cym. Saint Raphin×Cym. Longibracteatum 2n=2x=34m+6sm,As.k=57.15℅.According to Stebbins classification of karyotypic asymmetry,all of the karyotypes belong to“2B”. Moreover, with some stably specialized traits in morphology, the evolution of karyotypes in Cymbidium were also discussed.