Genetic evidence for the allodiploid origin of the moss species Polytrichum longisetum

Fixed heterozygous banding patterns observed for 4 allozyme and 12 microsat ellite loci, in combination with a chromosome number of 14, show that Polyt richum longisetum is an allodiploid species. Comparison of these banding pa tterns with those of related Polytrichaceae species suggest that Polytrichu m formosum, or an ancestor taxon of this species, is one of the haploid pro genitors of P. longisetum. The second progenitor species of P. longisetum c ould not be designated in this study as it was not among the examined possi ble progenitor species. DNA sequence data for two microsatellite loci, howe ver, suggest that the second progenitor species should possibly be more clo sely related to P. formosum than any of the other haploid possible progenit or species examined in this study. As the current systematic literature doe s not mention the existence of such a species, this could indicate that the second progenitor species is already extinct.