Abstract Detail

Mycological Section

Doering, Jennifer [1], Toni, Sydney [1], Lewis, Chris [2], Bazin, Ron [3], Piercey-Normore, Michele D. [1].

The rare lichen, Leptogium rivulare, from rock and tree bark is a single species and the mycobiont has a low level of photobiont selectivity.

Some lichens can grow on more than one type of substratum but others are highly specific to a particular type of substratum. The lichen, Leptogium rivulare is designated as threatened in Canada by COSEWIC, and it grows on rock and tree bark which also coincides with different geographic locations in Manitoba and Ontario. Since L. rivulare is considered to be a threatened species, the question of species designation was raised for the thalli that occur on different substrata. Additionally, the role of photobiont in the species designation, the substratum, and the geographic location was also raised. The goal of this study was to test the monophyly of the species from rock and tree dwelling locations for both symbionts. The fungal internal transcribed spacer of the nuclear ribosomal DNA (ITS rDNA) and the cyanobacterial tRNA^Leu (trnL) genes were sequenced producing 11 trnL sequences (5 from tree bark and 6 from rock) and 16 ITS rDNA sequences (10 from tree bark and 6 from rock) The fungal phylogeny showed that all sequences fall within a single clade with 97% bootstrap support. The cyanobacterial tree shows that Nostoc sequences from rock and tree bark mix with one another and that Nostoc from other sources also fall within the same clade. These results suggest that the mycobiont is genetically the same species based on the ITS rDNA and can live on rock or tree bark. The results also suggest that the Nostoc strain from the L. rivulare thallus samples are neither specific to the substrate on which the lichen grows nor to the geographic location. Additionally, other lichen fungi that associate with Nostoc may contribute to the pool of available cyanobacterial partners for L. rivulare.

1 - University of Manitoba, Department of Biological Sciences, 509 Buller Building, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada
2 - Ministry of Natural Resources, Peterborough, ON, K9J 8M5, Canada
3 - Environment Canada, Canadian Wildlife Service, Winnipeg, MB, R3C 4W2, Canada

Keywords:
mycobiont selectivity
photobiont
rare lichen
ITS rDNA
trnL.

Presentation Type: Oral Paper:Papers for Sections
Session: 56
Location: Salon 1/The Shaw Conference Centre
Date: Wednesday, July 29th, 2015
Time: 9:15 AM
Number: 56006
Abstract ID:1162
Candidate for Awards:None