Abstract Detail

Bryology and Lichenology

Widhelm, Todd [1], Grewe, Felix [1], Huang, Jen-Pan [2], Ramanauskas, Karolis [3], Mason-Gamer, Roberta [4], Lumbsch, Helge [5].

Using RADseq to understand the circum-Antarctic distribution of the lichenized fungus Pseudocyphellaria glabra (Ascomycota, Peltigeraceae).

Aim: The lichenized fungus Pseudocyphellaria glabra has a disjunct distribution that is separated by the Tasman Sea and the Pacific Ocean. We collected samples from across its disjunct range to test whether major physical barriers resulted in genetic differentiation among populations. We tested two hypotheses (1) if large bodies of water isolate populations of P. glabra, then these populations will be genetically distinct, and (2) given the strong wind patterns in the southern hemisphere, P. glabra populations on different landmasses will be connected by frequent and ongoing long-distance dispersal (i.e. gene-flow). We predicted the that the large distances between populations would generate genetically distinct clusters, but given the strong and sustained wind patterns present in the Southern Hemisphere and the microscopic size of P. glabra spores that migration is frequent enough to prevent speciation.
Location: Southeastern Australia, New Zealand, and Southern Chile
Methods: We used genomic data from 286 samples of two species using restriction site-associated DNA sequencing to conduct phylogenomic and population genomic analyses.
Results: Maximum likelihood analysis recovers P. glabra as a well-supported monophyletic clade with four distinct lineages that do not correspond to geography. Two of the major lineages contain individuals from all landmasses. Population genomic analyses show that samples from Australia, Chile, and New Zealand form three genetic clusters that are isolated by the Tasman Sea and Pacific Oceans. Co-ancestry estimation analyses suggest that populations from New Zealand and Chile have higher levels of co-ancestry than both do with Australian populations.
Main conclusion: Populations from Australia, Chile, and New Zealand are genetically distinct, but frequent long-distance dispersal may sufficiently prevent speciation.

1 - Field Museum, 1400 S. Lake Shore Drive, Chicago, IL, 60605, United States
2 - Academia Sinica, Biodiversity Research Center, 128 Academia Road, Sec. 2, Taipei , Nankang, 11529, Taiwan
3 - University of Illinois at Chicago, 845 W. Taylor St., Chicago, IL, 60607, United States
4 - University Of Illinois At Chicago, DEPT. OF BIOLOGICAL SCIENCES (M/C 066), 845 W. Taylor St., Chicago, IL, 60607, United States
5 - Department Of Botany, 1400 S. Lake Shore Drive, Chicago, IL, 60605, United States

Keywords:
biogeography
population genetics
lichenized fungi
RADseq.

Presentation Type: Oral Paper
Session: LICH1, Lichenology
Location: San Pedro 2/Starr Pass
Date: Monday, July 29th, 2019
Time: 2:15 PM
Number: LICH1004
Abstract ID:245
Candidate for Awards:None