EVALUATION OF THE EXTENT OF GENETIC-VARIATION IN MAHOGANIES (MELIACEAE) USING RAPD MARKERS

Despite the economic importance of mahoganies Meliaceae) little is kno wn of the pattern of genetic variation within this family of tropical trees. We describe the application of a polymerase chain reaction (PCR )-based polymorphic DNA assay procedure random amplified polymorphic D NAs (RAPDs) to assess the extent of genetic variation between eight ma hogany species from four genera. Pronounced genetic differentiation wa s found between the species and genera. There was a clear separation o f Cedrela odorata from the other species, with 95% of the variable amp lification products differing, whereas Lovoa trichilioides, Khaya spp. and Swietenia spp. were more closely grouped. These results are consi stent with the current taxonomic viewpoint. A number of markers were f ound to be diagnostic for particular species, which could be of value in determining the status of putative hybrids. The application of RAPD s to the study of genetic variation in mahoganies is discussed in the context of developing genetic conservation and improvement strategies for these species.