Journal Article

The Lichen-Forming Ascomycete Evernia mesomorpha Associates with Multiple Genotypes of Trebouxia jamesii

Piercey-Normore, Michele D.

2006

Overview

• The epiphyte Evernia mesomorpha forms a lichen association with green algae in the genus Trebouxia. Little is known about the population structure of E. mesomorpha. Here, population structure of the algal and fungal symbionts was examined for 290 lichen thalli on 29 jack pine (Pinus banksiana) trees in Manitoba. • Through phylogenetic analysis of internal transcribed spacer (ITS) nuclear ribosomal DNA (rDNA) sequences, five algal genotypes were detected that were nested within T. jamesii. Two fungal genotypes were detected that formed a clade with two other Evernia species. The genus Evernia was paraphyletic with E. prunastri, sister to Parmelia saxatilis. Restriction fragment length polymorphism (RFLP) of ITS rDNA showed multiple algal genotypes in 45% of the 290 lichen thalli collected, whereas all thalli only contained one fungal genotype. • Low population subdivision of algal and fungal genotypes among trees suggested that the algal symbiont was being dispersed in the lichen soredium. • Low fungal specificity for multiple algal genotypes and a hypothesized algal switch may be important life history strategies for E. mesomorpha to adapt to changing environmental conditions.

• Publisher: Blackwell Science,Blackwell Publishing Ltd,Blackwell
• Subject: Actins / Algae / algal dispersal / algal switch / Animal and plant ecology / Animal, plant and microbial ecology / Ascomycetes / Ascomycota / Ascomycota - genetics / Ascomycota - metabolism / Biological and medical sciences / Biological taxonomies / Demecology / DNA, Fungal / DNA, Fungal - genetics / DNA, Intergenic / DNA, Intergenic - genetics / DNA, Plant / DNA, Plant - genetics / environmental factors / epiphytes / Eukaryota / Eukaryota - genetics / Eukaryota - metabolism / Evernia mesomorpha / Evernia mesomorpha / founder effect / Fundamental and applied biological sciences. Psychology / fungal specificity / Fungi / Genetic Variation / genetics / Genotype / Genotypes / internal transcribed spacers / Lecanorales / lichen algae / Lichens / life history / Manitoba / metabolism / paraphyly / Parmelia / Parmelia saxatilis / Phylogeny / Pine trees / Pinus banksiana / Plants and fungi / Population structure / restriction fragment length polymorphism / Ribosomal DNA / sequence analysis / symbionts / Symbiosis / Thallus / transcription (genetics) / Trebouxia / Trebouxia jamesii / Trebouxia jamesii / trees