Bryological and Lichenological Section/ABLS
Fontaine, Kyle , Sorensen, John , Piercey-Normore, Michele .
Growth and species differentiation in Cladonia rangiferina and C. stygia.
Reindeer and caribou rely on Cladonia rangiferina and C. stygia as a winter food source. These closely related lichens grow in different habitats and have few diagnostic features but have been considered the same species until 1985 when they were separated. Growth is from the younger tips of the branches leaving the older lower parts to degenerate, but secondary compounds are still present in the older parts of the thallus. It is unknown whether these compounds are being produced from living basal tissue, being transported from younger upper tissue, or simply trapped within the medullary hyphae of the thallus. The objectives of this study were 1) to determine whether the genetic variability supports the morphological species concept in C. rangiferina and C. stygia, and 2) to investigate why secondary compounds remain in the older part of the thallus. Differences investigated include features of the photobiont, the mycobiont, and secondary compounds relative to genetic, geographic, and chemical variation. The fungal and algal internal transcribed spacers of the ribosomal DNA (ITS rDNA) were sequenced for phylogenetic analysis, complementary DNA (cDNA) was synthesized from the total messenger RNA (mRNA) to investigate transport and metabolic activity in thallus tissue, and High Performance Liquid Chromatography (HPLC) was performed to determine the levels of compounds present in thallus portions. Photobiont variation suggests some geographic relationships from east to west, the ratio of atranorin to fumarprotocetraric acid is higher in the upper thallus than the lower thallus, and the lower thallus shows no metabolic or transport activity. Species relationships and thallus growth will be discussed with respect to phenotypc plasticity and polyketide production.
Log in to add this item to your schedule
1 - University of Manitoba, Department of Biological Sciences, Winnipeg, Manitoba, R3T 2N2, Canada
2 - University of Manitoba, Department of Chemistry, Winnipeg, Manitoba, R3T 2N2, Canada
Presentation Type: Oral Paper:Papers for BSA Sections
Location: Superior B/Cliff Lodge - Level C
Date: Tuesday, July 28th, 2009
Time: 10:30 AM