Genetic diversity within and across gametophytic ploidy levels in a Sphagnum cryptic species complex

We deploy Shannon analysis of five ancestrally (ANCE) diagnostic microsatellite loci to explore the patterns of `deep' allelic genetic diversity within the peat moss Sphagnum australe Mitt. s.l. cryptic species complex across its Australasian distribution. There is both notable divergence among and considerable allelic overlap within the three allopolyploid lineages of this complex, two gametophytically allodiploid (R1S1 and R2S2) and one gametophytically allotriploid (FR1*S1*). Detailed biogeographic patterns reflect historical differences in genetic isolation and interbreeding. Lineage I (R1S1) occurs in both Australia and New Zealand, while Lineage II (R2S2) and Lineage III (FR1* S1*) are endemic to New Zealand, where Lineage III predominates. Available data suggest that Lineage I arose in Australia, whereas both Lineage II and Lineage III originated in New Zealand. `Deep' allelic diversity provides a pronounced signal of evolutionary radiation within and among the three lineages. We develop a methodology to explore allelic diversity across ploidy levels and elaborate another for scaling additive allele-metric diversity values [0,1], relative to attainable minimal and maximal values, given the sampling frame. We suggest the following taxonomic disposition: gametophytically allodiploid Lineages I and II ! S. australe; gametophytically allotriploid Lineage III ! S. antarcticum. Epitypes are designated for both species.