Morphologically cryptic biological species within the liverwort Frullania asagrayana

Abstract

The genetic structure of F. asagrayana in eastern North America reflects morphologically cryptic differentiation between reproductively isolated groups of populations, near-panmixis within groups, and clonal propagation at local scales. Reproductive isolation between groups that are invariant at the level of nucleotide sequences shows that caution must be exercised in making taxonomic and evolutionary inferences from reciprocal monophyly (or lack thereof) between putative species.

Bryophyte diversity and evolution: Windows into the early evolution of land plants

“…Other recent studies using highly polymorphic markers (e.g., microsatellites, AFLP, ISSR) show that dispersal is suffi cient even at continental scales to genetically homogenize plants ( van der Velde and Bijlsma, 2003 ;Cronberg, 2002 ;Grundmann et al, 2007Grundmann et al, , 2008Vanderpoorten et al, 2008 ). An absence or near absence of linkage disequilibrium within the liverwort Frullania asagrayana across a large portion of eastern North America indicates both extensive dispersal and a level of sexual recombination that approaches panmixia ( Ramaiya et al, 2010 ). It should be noted, on the other hand, that few bryophyte species are ubiquitous at regional let alone global scales, and clearly, successful dispersal and establishment are limited.…”

The application of molecular data to the phylogenetic delimitation of species in bryophytes: A note of caution

“…In the Frullania tamarisci (L.) Dumort. complex, for example, nucleotide sequences from two generally variable plastid loci, trnL and trnG, and the nuclear ribosomal ITS region, revealed virtually no variation and no phylogenetic structure within the eastern North American species, F. asagrayana Mont., sampled from North Carolina to Maine (Ramaiya et al 2010). However, variation at 12 hypervariable microsatellite loci revealed two well defined groups of populations, one generally northern in distibution and the other southern.…”

Morphology informed by phylogeny reveals unexpected patterns of species differentiation in the aquatic moss Rhynchostegium riparioides s.l.

“…In bryophytes, cryptic speciation has been increasingly reported (e.g., Heinrichs et al, 2010;Kreier et al, 2010;Orzechowska et al, 2010;Ramaiya et al, 2010) and might offer an explanation for one of the most striking biogeographic features of bryophytes, that is, the extremely low rates of endemism of their floras (see Vanderpoorten et al, 2010a for review). In Macaronesia for example, a biogeographic region comprised of the mid-Atlantic archipelagos of the Azores, Madeira, and the Canary Islands, and which is recognized as an important floristic area for conservation within the European-Mediterranean climate region (Médail and Quezel, 1997), less than 2% of species are endemic to the Canarian archipelago, strongly paling in comparison with the 40% endemism rates observed in angiosperms (Vanderpoorten et al, 2010a).…”

“…For instance, a combination of four loci including rbcL and matK allowed a species resolution of only 65% in a set of Chinese Grimmiaceae (Liu et al, 2011). More variable regions of the genome, and nuclear microsatellites in particular, have therefore increasingly been used in moss species-level systematics (e.g., Caruso et al, 2010;Harbaugh et al, 2011;Karlin et al, 2008Karlin et al, , 2011Korpelainen et al, 2008;Peros et al, 2011;Ramaiya et al, 2010).…”