Resolving boundaries between species in Sphagnum section Subsecunda using microsatellite markers

Populations and species of Sphagnum section Subsecunda are morphologically variable and it is often difficult from studying field-collected plants and herbarium specimens to delimit species. Allelic patterns at 20 microsatellite loci indicate that three distinguishable gene pools can be identified among plants from Australia and New Zealand. All three species are morphologically variable along a moisture gradient and this appears to be largely plastic, without genetic differentiation among species specific morphotypes. Sphagnum novozelandicum and S. comosum appear to have monoploid gametophytes, are closely related, and are endemic to Australia and New Zealand. The former usually occurs at or above water level and the latter is an aquatic plant with extensive morphological variation, ranging from simplex to branched morphotypes. Sphagnum fuscovinosum and S. simplex are synonyms of S. comosum. The third species is a highly disjunct population of the S. auriculatum/S. inundatum complex of Europe, which has not previously been reported for Australia and New Zealand. These plants appear to be polyploid and are genetically and morphologically distinct from both S. novo-zelandicum and S. comosum. All three species had duplicated loci amplified by one of the microsatellite primer pairs. Ten Sphagnum species are now reported for Australia and New Zealand, with three of these being endemic.

Duke Scholars

Author A. Jonathan Shaw Biology