Abstract Detail

Bryological and Lichenological Section/ABLS

Doering, Jennifer [1], Piercey-Normore, Michele D. [1].

Population structure and spatial variation in Diplosphaera chodatii in semi-aquatic lichen communities of Payuk Lake, Manitoba.

The Silverskin lichen (Dermatocarpon luridum) grows along the shores of lakes and streams where water levels fluctuate, and the species is known as a pollution indicator. Dermatocarpon luridum associates with the unicellular green alga Diplosphaera chodatii, a free-living alga which has been placed phylogenetically among other algae such as Stichococcus spp., but little is known about its genetic diversity and spatial ecology. By studying the spatial and temporal variation of these populations, the population structure can be understood and dispersal and other processes may be inferred. This project aims to determine if there is spatial and temporal variation among populations of the lichenised alga Diplosphaera chodatii in Payuk Lake, Manitoba. Samples were collected during fall 2014 and spring 2015 and the DNA was extracted. The algal internal transcribed spacer region of the nuclear ribosomal DNA (ITS rDNA), part of the type I actin, and ribulose carboxylase-oxidase (rbc-L) genes were sequenced. Sequences from 2010 were obtained from a previous study in the same location. The preliminary results show at least twelve ITS rDNA haplotypes, where two haplotypes are unique and two other haplotypes are common. Most of the variation occurred within the ITS2 region of the ITS rDNA gene. Results also show that some of the same haplotypes are present over time, as might be expected since the lichen thallus is perennially attached to shoreline rocks, but other haplotypes differ with time. A higher level of diversity was found near the faster flowing water at the mouth of a creek into the lake. Additional haplotypes were found in a bay that experiences high levels of human activity and at a second, slower-moving inflow creek, indicating that new haplotypes may be entering the lake from upstream sources. Furthermore, some haplotypes are spread throughout the lake, suggesting some circulation of haplotypes within the lake system. Knowledge of how the semi-aquatic lichen communities form and the biology of the photobionts associated with Dermatocarpon luridum will improve our understanding of the photobiont dispersal and the sensitivity of D. luridum to water pollution and its widespread use as a pollution indicator.

1 - University of Manitoba, Department of Biological Sciences, 509 Buller Building, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada

Keywords:
Diplosphaera chodatii
lichens
boreal
population structure
genetic variation
lichenised algae
spatial variation
temporal variation.

Presentation Type: Poster:Posters for Sections
Session: P
Location: Hall D/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 5:30 PM
Number: PBR006
Abstract ID:504
Candidate for Awards:Ian and Syvia Taylor Award