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 v ariance analysis (HOMOVA), and cluster analysis to describe the popula tion genetic structure of Ihiamna corei, a federally endangered plant located only in Virginia, and I. remota, a rare plant in Virginia, Ind iana, and Illinois. The analysis was performed to help clarify the tax onomic relationship between the two closely related species. We analys ed four clones in the only known population of I. corei, breeding stoc k derived from seeds originating from the population site, and three I . remota populations in Virginia. Eighty-five percent of screened prim ers revealed DNA polymorphisms in Ihiamna. Ninety-nine informative mar kers were generated using seven primers. No significant statistical di fferences (at P = 0.05) in RAPD variation was found between species (2 4% of variance) using the AMOVA procedure. However, within species/amo ng populations (31% of the variance) and within populations (45% of th e variance) there were significant differences (P < 0.002). An unweigh ted paired group method using arithmetic averages (UPGMA) cluster anal ysis showed the federally endangered I. corei population to be genetic ally distinct from the apparently recently introduced (in Virginia: si milar to 100 ybp) I. remota. The lack of significant differences from the AMOVA and the high number shared bands between I. corei and I. rem ota suggest that I. corei may be more appropriately classified as a su bspecies of I. remota. Ihiamna corei plants in the natural population were genetically similar to one another while the I. corei breeding st ock plants and I. remota plants were genetically relatively diverse. ( C) 1996 The Linnean Society of London