Abstract
To determine genetic variation in the apogamous fern species Dryopteris nipponensis, allozyme analysis was carried out. Among the 196 individuals of D. nipponensis examined, 45 electrophoretically distinguishable variants were detected. This is the largest number of electrophoretic variants found in one apogamous fern species so far examined. Only one variant was characterized by a unique allele. All of the other variants were distinguished by the combinations of the limited number of alleles that were shared by some variants. The evidence strongly suggests that this apogamous species is of recurrent origin. The possibility of homoeologous chromosome pairing was also evaluated. Theoretically, genotypes of twelve of 45 variants can be generated from those of other variants via homoeologous chromosome pairing.
