Genetic relationship and differentiation of Paphiopedilum and Phragmepedium based on RAPD analysis

The genetic diversity and relationship between Paphiopedilum and Phragmipedium species and cultivars was determined by randomly amplified polymorphic DNA (RAPD) analysis. Twenty-one species and 13 varieties of these two orchids genera were analyzed and the similarity values ranged from 0.629, between P. kolosand and Paphiopedilum koloparkngii, to 0.882, between P. koloparkingii and Phragmipedium ‘Hanne Popow’. The analysis included both total and polymorphic band scores. The orchids examined could be separated into two major subgroups. The first major subgroup, subgroup I, included 28 species, which was composed of all Paphiopedilum species and 8 Phragmipedium species. Subgroup II was comprised of six species. These two subgroups could be further divided into two minor clusters. In this study Paphiopedilum and Phragmipedium were successfully differentiated by RAPD and the results were in good agreement with morphological based classifications. Therefore, our results suggest that the phylogenetic information could be obtained using molecular markers to address the interspecies genetic relationships of Paphiopedilum and Phragmipedium.