Electrophoretic Evidence for Inbreeding in the Fern Botrychium Virginianum (Ophioglossaceae)

An electrophoretic investigation of Botrychium virginianum was conducted to determine the levels and distribution of genetic variation within and among populations of this species. A total of 18 loci representing seven enzymes was examined. For the four polymorphic loci, observed heterozygosity was substantially lower than expected heterozygosity. Values of F were extremely high, indicating a significant deviation from random mating, probably due to inbreeding. We suggest that the high inbreeding coefficients obtained result from a life cycle involving subterranean gametophytes which restrict sperm movement. The study also demonstrates the value of using F‐statistics and gene diversity statistics to analyze genetic subdivision in a fern species. Despite the high chromosome number reported for B. virginianum (n = 90), there is no genetic evidence to support the contention that this species is highly polyploid.