Levels and Patterns of Genetic Variation in Isoëtes karstenii with Observations on I. palmeri

Genetic variation was surveyed in eleven populations from throughout the range of the diploid Isoëtes karstenii, as well as in two populations of a closely related tetraploid, I. palmen, using allozyme electrophoresis. Genetic variation was high in I. karstenii and appears to be highly structured, as evidenced by analyses of F-statistics and genetic vs. geographic distance. No fixed unique alleles were found that could distinguish between I. karstenii and I. palmeri, although one allele was observed that was unique to I. palmeri. These analyses confirm earlier observations suggesting low levels of interpopulational gene flow and have implications for sampling strategies.