Population genetic variation in rare and endangered Iliamna(Malvaceae) in Virginia

Random amplified polymorphic DNA (RAPD) markers were used as input for an analysis of molecular variance (AMOVA), homogeneity of molecular variance analysis (HOMOVA), and cluster analysis to describe the population genetic structure of Iliamna corei, a federally endangered plant located only in Virginia, and I. remota, a rare plant in Virginia, Indiana, and Illinois. The analysis was performed to help clarify the taxonomic relationship between the two closely related species. We analysed four clones in the only known population of I. corei, breeding stock derived from seeds originating from the population site, and three I. remotapopulations in Virginia. Eighty-five percent of screened primers revealed DNA polymorphisms in Iliamna. Ninety-nine informative markers were generated using seven primers. No significant statistical differences (at P = 0·05) in RAPD variation was found between species (24% of variance) using the AMOVA procedure. However, within species/among populations (31% of the variance) and within populations (45% of the variance) there were significant differences ( P < 0·002). An unweighted paired group method using arithmetic averages (UPGMA) cluster analysis showed the federally endangered I. coreipopulation to be genetically distinct from the apparently recently introduced (in Virginia: ≈ 100 ybp) I. remota. The lack of significant differences from the AMOVA and the high number shared bands between I. coreiand I. remotasuggest that I. coreimay be more appropriately classified as a subspecies of I. remota. Iliamna coreiplants in the natural population were genetically similar to one another while the I. coreibreeding stock plants and I. remotaplants were genetically relatively diverse.