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

• Published in: The New phytologist Vol. 169; no. 2; pp. 331 - 344
• Main Author: Piercey-Normore, Michele D.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science 01.01.2006; Blackwell Publishing Ltd; Blackwell
• Subjects: Actins; Algae; algal dispersal; algal switch; Animal and plant ecology; Animal, plant and microbial ecology; Ascomycetes; Ascomycota - genetics; Ascomycota - metabolism; Biological and medical sciences; Biological taxonomies; Demecology; DNA, Fungal - genetics; DNA, Intergenic - genetics; DNA, Plant - genetics; Eukaryota - genetics; Eukaryota - metabolism; Evernia mesomorpha; Evernia mesomorpha; Fundamental and applied biological sciences. Psychology; fungal specificity; Fungi; Genetic Variation; Genotype; Genotypes; lichen algae; Lichens; Parmelia saxatilis; Phylogeny; Pine trees; Pinus banksiana; Plants and fungi; Population structure; Ribosomal DNA; Symbiosis; Thallus; Trebouxia jamesii; Trebouxia jamesii; Symbiosis; Life history; population structure; Taxonomy; Algae; Epiphyte; Ribosomal DNA; Evernia mesomorpha; Trebouxia jamesii; Genotype; algal switch; Phylogeny; fungal specificity; lichen algae; Restriction fragment length polymorphism; Chlorophyta; Vegetative apparatus; Lichenes; algal dispersal; Thallophyta; Adaptation
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/j.1469-8137.2005.01576.x

• 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.