Bryological and Lichenological Section/ABLS
Liu, Yang , Medina, Rafael , Wilding, Nicholas , Budke, Jessica , Hedderson, Terry , Goffinet, Bernard .
The evolutionary history of Physcomitrella patens: phylogenetic inferences from 4 loci within the Funariidae.
Physcomitrella patens is characterized by tiny ephemeral vegetative plants and a nearly sessile sporangium lacking a peristome and a differentiated dehiscence line. Its ability to complete its life cycle rapidly made it a good system for developing protocols for protoplast isolation and transformation via homologous recombination. Ultimately Physcomitrella rose to become a model system in plant developmental genetics, with a central role in furthering our understanding of the evolution of developmental networks in land plants. The contribution of Physcomitrella genomics to our understanding of the evolution of the moss body remain underexplored yet considering the systematic affinities of this taxon, the opportunities are immense. Physcomitrella belongs to the Funariaceae, a speciose family characterized by a broad amplitude in sporophytic complexity. A short indehiscent capsule is shared by multiple species from various genera, and likely arose via reduction from a complex architecture represented by Funaria hygrometrica, with long sporophytes, asymmetric capsules, complex annuli triggering the dehiscence and complete, double peristomes lining the capsule mouth. Phylogenetic inferences from 10 loci previously demonstrated that sporophytic architecture was labile within the crown group of Funariaceae, comprising at least 80% of the species diversity, and that reductionary shifts likely arose multiple times. The three taxa of Physcomitrella, formerly regarded as either distinct species, varieties, or even conspecific entities, belong to three clades within the Physcomitrium complex. The phylogenetic relationships within the crown group remained mostly ambiguous. In this study we have broadened the taxon sampling to nearly 200 accessions for which 4 loci were sequenced, which enhanced the circumscription of the clades but failed to resolve their relationships. The phylogenetic pattern observed is symptomatic of an evolutionary history marked by a rapid diversification. Estimated times of cladogenic events suggests that divergence of the crown group began 50 mya followed by an explosive diversification not later than 25 mya. The rapid radiation is marked by multiple shifts in the complexity of the sporophytic architecture. Such scattered distribution of taxa with reduced morphologies, within a lineage that includes a model system in plant genomics provides an excellent opportunity to study the genetic causes underlying the developmental parallelism. We are currently aiming to resolve the circumscription of and the relationships among clades in the Funariaceae using inferences from entire organellar exomes sampled via liquid phase gene enrichment to provide a robust phylogenetic framework for testing hypotheses on the evolution of developmental networks within this complex of moss species.
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1 - University of Connecticut, 75 NorthEagleville road, Storrs, Connecticut, 06269, United States
2 - University of Connecticut, Ecology and Evolutionary Biology, 75 NorthEagleville road, Storrs, Connecticut, 06269, United States
3 - University of Cape Town, Department of Biological Sciences, Private Bag, Rondebosch, 7701, South Africa
4 - University of California Davis, Plant Biology, One Shields Avenue, Davis, CA, 95616, USA
5 - University Of Connecticut, Department Of Ecology & Evolutionary Biology, 75 N. Eagleville Road, U-3043, STORRS, CT, 06269-3043, USA
Presentation Type: :Papers for Sections
Location: Ascot/Riverside Hilton
Date: Tuesday, July 30th, 2013
Time: 1:30 PM
Candidate for Awards:None