Opuntia

The population decline in the Florida Semaphore cactus, Opuntia corallicola, due to grazing by the moth, Cactoblastus cactorum, has placed this plant species on the verge of extinction in the Florida Keys. Although this semaphore cactus is endemic to Florida, it was mis-named as an almost uncommon Jamaican species (Opuntia spinosissima) in the 1970s. Our goal was to provide genetic data to distinguish these cacti with nuclear and chloropast genes previously used in other plant phylogenetic analyses. Phylogenetic relationships were inferred from nucleotide sequence variation in both the Leucine-Phenylalanine transfer RNA intergenic spacer (trnL-trnF) and ribulose bisphosphate carboxylase-oxygenase (rbcL) genes of cactus chloropast DNA. While the trnL-trnF gene sequence data could only group cacti at the genus level, it was the data from the rbcL gene which show speciation and differences between the Florida Semaphore cactus, Opuntia corallicola, and the Jamaican species, Opuntia spinosissima. Sequence data from the internal transcribed spacer (ITS) regions of nuclear DNA were not available due to the divergence of the cactus ITS region from the universal primers sequences used to initiate the polymerase chain reaction (PCR).