ISOZYVME EVIDENCE OF RELATIONSHIPS WITHIN SPHAGNUM SECT ACUTIFOLIA (SPHAGNACEAE, BRYOPHYTA)

Ten enzyme systems coding for 13 putative loci were studied in 12 Euro pean species of Sphagnum sect. Acutifolia (peat mosses). On average se ven plants from each of 73 collections made throughout N Europe were a nalysed. Despite complex morphological variation, all species expresse d unique allele combinations. Principal components and cluster analyse s based on allele frequencies showed that sect. Acutifolia can be divi ded into two major groups; one comprising Sphagnum fimbriatum, S. girg ensohnii and S. molle; the second comprising S. capillifolium, S. ange rmanicum, S. fuscum, S. quinquefarium, S. rubellum, S. subfulvum, S. s ubnitens and S. warnstorfii. These groups are linked by S. russowii, w hich is shown to be an allopolyploid, with fixed heterozygosity at 6 t o 8 of the loci. The presumed progenitors of S. russowii are S. girgen sohnii and S. rubellum. Allelic data also indicate that S. teres from sect. Squarrosa is related to S. girgensohnii and S. fimbriatum. The b isexual species tend to be less variable than the unisexual species.