Genetic and morphological variation in the rare epiphytic moss Neckera pennata Hedw.

Fifteen Swedish populations of the threatened epiphytic moss Neckera pennata Hedw. were surveyed for genetic variation by use of enzyme electrophoresis. Seven genotypes were detected from 12 scored loci. The genotypes could be divided into two groups, with specific alleles at four loci. The genetic identity between the genotype groups (0.641) is comparable to identities between congeneric species based on previous studies of mosses. Moreover, these groups occurred sympatrically with no apparent sexual recombination, implying the possibility of sibling speciation. A morphological analysis revealed minor differences between the genotype,groups. Possible reasons for the lack of recombinant genotypes are discussed. In addition, genetic and morphological analyses were performed to compare N. pennata and N. oligocarpa Bruch, which are considered distinct species by some bryologists and varieties of the same species by others. Clear morphological differences and a genetic differentiation of the same magnitude as the genotype groups of N. pennata were revealed.