Abstract: Cymbidium is a genus with very important values of horticulture. In the present study genetic closeness of various species of Cymbidium was determined using RAPD. A total of 250 amplified bands was gotten from all PCR reactions by 12 selected primers, and their band size was from 200 bp to 2 100 bp. Except of the 850 bp band amplified from S143 primer, all other amp lified bands were diversity locus, and most of the bands were located between 1 030 bp and 300 bp. The UPGMA dendrogram showed some congruence with the previous ITS phylogeny, which revealed the paraphyly of subgen. Cyperorchis, and high polyphyly of subgen. Cymbidium. The subgroups within each subgenus revealed by the RAPD were, however, correspond to the traditional taxonomy based on gross morphology. This study also shows higher genetic diversity of C. goeringii, being cultived for long history, than other Cymbidium species.

Key words: Cymbidium, Orchidaceae, RAPD