Comparison of RAPD marker patterns to morphological and physiological data in the classification of Opuntia accessions

An analysis of morphological, physiological, and molecular data from five cactus fruit varieties from Mexico and Chile, two ornamental Texas accessions, and one vegetable accession from Mexico are presented. Molecular analysis was performed using the RAPD (random amplification of polymorphic DNA) method. Phenotypic and molecular analyses distinguished ornamental, vegetative, and fruit market accessions of Opuntia ellisiana, O. lindheimerii, O. cochinellifera, O. hyptiacantha, and O. ficus-indica from each other, and suggested significant differences among accessions of different market classes. Differences among fruit cultivars were smaller, and, in conjunction with the previously reported cross-compatibility among them, suggests that species designations may need to be reconsidered. The results demonstrate the feasibility of DNA fingerprinting in Opuntia.