Erigeron kachinensis, the Kachina daisy, is a rare species restricted to hanging gardens of canyons in southeastern Utah. The species exhibits low fecundity due to low percent fertilization of ovules and high percent abortion of fertilized ovules. Reproductive data suggest that low fecundity is a consequence of small population size and inbreeding depression. This study examines genetic diversity within and among populations of E. kachinensis in Natural Bridges National Monument using twelve variable isozyme loci generated through electrophoretic techniques. These loci are used to calculate genetic diversity statistics for this species. Populations are found to have significantly different morphologies and resistance to predators/pathogens suggestive of genetic drift. However, genetic diversity statistics demonstrate that only 22.8% of genetic variation is distributed among populations. Genetic distance could not be correlated with geographic distance indicating that populations may share alleles through common ancestry and not recent gene flow events. Observation of genotype frequencies demonstrates that populations are fixing on different genotypes and may be experiencing initial stages of genetic drift. Mean observed heterozygosity is 0.166 and is found to increase with increasing size class in the populations.

Key words: Asteraceae, Erigeron kachinensis, genetic drift, genetic variability