Species delimitation and relationships of the Sphagnum recurvum complex (Bryophyta) - as revealed by isozyme and RAPD markers

Isozyme data from 26 populations of six species within the Sphagnum recurvu m complex, as well as from the two outgroups S. balticum and S. lindbergii, were used to infer the relationships of these populations, and to assess t o what degree these relationships are reflected in alternative classificati ons. A subset of eight populations, comprising four species, were analyzed for both isozyme and RAPD markers. Population aggregation analysis, cluster analysis of pairwise distances and parsimony analysis of allele frequency data grouped populations with brown spores in three distinct clusters corre sponding to S. angustifolium, S. flexuosum and S, recurvum s. str., whereas no clusters corresponding to any of the yellow-spored tara (S. brevifolium , S. fallax and S, isoviitae) could be discerned. Genetic data corroborates morphological evidence suggesting that species level recognition is not wa rranted for S, fallax and S, isoviitae, whereas the status of S. brevifoliu m remains more uncertain. S. lindbergii deviated strongly from the remainin g material in terms of both isozymes and RAPDs supporting its status as out group. S. balticum showed close genetic affinity to the yellow-spored taxa, suggesting that the S. recurvum complex is not monophyletic. Isozyme and R APD markers yielded similar clustering patterns.