| Abstract Detail
Bryology and Lichenology Parker, Dinah [1], Goffinet, Bernard [1]. One fungus-two lichens: Dendriscocaulon intricatulum is the cyanomorph of the Eastern North American endemic Ricasolia quercizans (Lobariaceae). Lichens are typically bipartite symbiotic associations involving a fungal partner, the mycobiont, and a photosynthetic partner, the photobiont, which is either a green alga or a cyanobacterium. However, a subset of lichens within the order Peltigerales form tripartite associations, where the fungus recruits both a green alga and a cyanobacterium to form the lichen, with both partners being photosynthetically active. Some tripartite lichens are unique in their ability to form photomorphs, or independent thalli with either both partners (chloromorph) or only with the cyanobacterium (cyanomorph). Dendriscocaulon is recognized as a cyanomorph form group of fruticose bipartite symbiotic associations formed by lichenized fungi typically developing foliose tripartite thalli with a green alga and Nostoc. Two species of Dendriscocaulon have been identified in North America: D. umhausense and D. intricatulum. Dendriscocaulon umhausense is widely accepted as the free-living form of the cephalodia of Ricasolia amplissima that may grow into shrubby outgrowths on the green thallus. Dendriscocaulon intricatulum is a dendriscocauloid cyanomorph from Eastern North America, but the corresponding chloromorph has yet to be identified. Phylogenetic inferences of sequences of the internal transcribed spacer (ITS) regions of the nuclear rDNA and the DNA-directed RNA polymerase II subunit (RPB1) sampled for several thalli of Dendriscocaulon from North America, and five candidate members of Ricasolia reveal that D. intricatulum and R. quercizans share the same mycobiont. Furthermore, analysis of the 16S rRNA region was used to determine patterns of cyanobacterial strains used in forming a Dendriscocaulon morph or the cephalodia of Ricasolia quercizans. Based on the identity of the mycobiont, the free-living Dendriscocaulon form in Eastern North America is considered to be developed solely by the endemic R. quercizans, and primarily towards the edge of the geographic distribution of the chloromorph. The name, D. intricatulum should be treated as the taxonomic synonym of R. quercizans.
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1 - University of Connecticut, Department Of Ecology & Evolutionary Biology, 75 North Eagleville Road, Storrs, CT, 06269, United States
Keywords:
chloromorph
photomorphs
photosymbiodemes
Peltigerales
symbiont
morphological plasticity
DNA barcodes
Taxonomic revision
cyanobacteria .
Presentation Type: Oral Paper
Session: 28, Bryology and Lichenology (ABLS) II
Location: Sundance 1/Omni Hotel
Date: Tuesday, June 27th, 2017
Time: 3:00 PM
Number: 28007
Abstract ID:445
Candidate for Awards:A. J. Sharp Award |
