Coevolution between algae and fungi in lichen associations

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Summary of proposed research Coevolution between algae and fungi in lichen associations Lichens are among the most understudied organisms and the most sensitive to environmental changes with little known about the co-evolving symbiotic partnership between algal and fungal symbionts that make up lichen associations. The widespread genus Cladonia contains species that grow in stable environments (Reindeer lichens; Cladonia rangiferina and allies) and species that grow in unstable disturbed sites (Pixie cup lichens; Cladonia pyxidata and allies). The objectives of this research are to examine patterns of genetic variation in each of the algal and fungal genomes and between symbionts for two groups of species that grow in different habitats (reindeer and pixie cup lichens) to determine: 1) evolutionary relationships among species and populations, 2) mode of reproduction and mating system, and 3) population structure for each of the symbionts. These objectives will be examined using nuclear and mitochondrial markers for each of the algal and fungal partners. This research will illustrate the importance of geographic and taxonomic scale in coevolutionary studies, that population level activity may determine coevolutionary relationships at higher taxonomic levels, and that there may be important differences in the mechanisms of adaptation between pioneer and climax lichens. These studies will also shed light on the understanding of adaptation in rare and endangered species or invasive and widespread species. This information is important for implementing science-based management strategies of natural resources.