Lichens; Population genetics; Symbiosis; Phylogeography; Photobiont-mediated guilds
Singh Garima, Dal Grande Francesco, Werth Silke, Scheidegger Christoph (2015), Long-term consequences of disturbances on reproductive strategies of the rare epiphytic lichen Lobaria pulmonaria: clonality a gift and a curse, in FEMS microbiology ecology
, 91(1), 1-11.
Dal Grande F., A. Beck, C. Cornejo, G. Singh, S. Cheenacharoen, M. P. Nelsen, C. Scheidegger (2014), Molecular phylogeny and symbiotic selectivity of the green algal genus Dictyochloropsis s. l. (Trebouxiophyceae): a polyphyletic and widespread group forming photobiont-mediated guilds in the lichen f, in New Phytologist
, 202(2), 455-470.
Werth S, Scheidegger C (2012), Congruent Genetic Structure in the Lichen-Forming Fungus Lobaria pulmonaria and Its Green-Algal Photobiont, in MOLECULAR PLANT-MICROBE INTERACTIONS
, 25(2), 220-230.
Widmer I, Dal Grande F, Excoffier L, Holderegger R, Keller C, Mikryukov VS, Scheidegger C (2012), European phylogeography of the epiphytic lichen fungus Lobaria pulmonaria and its green algal symbiont, in MOLECULAR ECOLOGY
, 21(23), 5827-5844.
Singh Garima, Dal Grande Francesco, Cornejo Carolina, Schmitt Imke, Scheidegger Christoph (2012), Genetic Basis of Self-Incompatibility in the Lichen-Forming Fungus Lobaria pulmonaria and Skewed Frequency Distribution of Mating-Type Idiomorphs: Implications for Conservation, in PLOS ONE
, 7, e51402.
Scheidegger C, Bilovitz PO, Werth S, Widmer I, Mayrhofer H (2012), Hitchhiking with forests: population genetics of the epiphytic lichen Lobaria pulmonaria in primeval and managed forests in southeastern Europe, in ECOLOGY AND EVOLUTION
, 2(9), 2223-2240.
Dal Grande F., Widmer I, Wagner HH, Scheidegger C (2012), Vertical and horizontal photobiont transmission within populations of a lichen symbiosis, in MOLECULAR ECOLOGY
, 21(13), 3159-3172.
Juriado I, Liira J, Csencsics D, Widmer I, Adolf C, Kohv K, Scheidegger C (2011), Dispersal ecology of the endangered woodland lichen Lobaria pulmonaria in managed hemiboreal forest landscape, in BIODIVERSITY AND CONSERVATION
, 20(8), 1803-1819.
Boch S, Prati D, Werth S, Ruetschi J, Fischer M (2011), Lichen Endozoochory by Snails, in PLOS ONE
, 6(4), 1-5.
Dal Grande F, Widmer I, Beck A, Scheidegger C (2010), Microsatellite markers for Dictyochloropsis reticulata (Trebouxiophyceae), the symbiotic alga of the lichen Lobaria pulmonaria (L.), in CONSERVATION GENETICS
, 11(3), 1147-1149.
Werth S (2010), Optimal sample sizes and allelic diversity in studies of the genetic variability of mycobiont and photobiont populations, in LICHENOLOGIST
, 43(1), 73-81.
Werth S (2010), Population genetics of lichen-forming fungi - a review, in LICHENOLOGIST
, 42, 499-519.
Lichens often have broad geographical distribution ranges and spread over more than one continent. Interpretations of such biogeographical pattern mostly include historical long-distance dispersal leading to the wide observed distribution of taxa or, alternatively, disjunct, but ecologically similar areas harbouring the remnants of a formerly more continuous distribution. In recent phylogeographic studies it was mainly the fungal partner of the lichen symbiosis that received attention. For the algal symbionts large-scale phylogeographic patterns are still incompletely understood and especially the relations between the phylogeographic patterns of the symbionts are still largely unknown. However, since lichens are morphologically highly integrated and ecologically obligate symbiotic systems, an combined study of the two (or more) symbionts is the only possible basis to obtain a complete phylogeographic and evolutionary understanding of the symbiosis. The aim of the present project is threefold: (1) to establish a worldwide phylogeography of the photobiont of L. pulmonaria; this results will be superimposed and integrated with the already available information of its fungal partner for identifying potential co-evolutionary hotspots of the lichen. (2) To analyse for the first time the spatial genetic structure of a lichen symbiosis. (3) To study the degree and nature of algal sharing within Lobariacean lichen communities. This would provide a rigorous test of the “photobiont-mediated guild” hypotheses, which supposedly drives the co-evolutionary processes in green algal lichens.In this project we will build on an already established phylogeography of the fungal partner of this symbiosis. For the photobiont of L. pulmonaria, Dictyochloropsis reticulata, we have recently developed highly variable microsatellite markers and will analyse the same samples (more than 6000) that were already analysed with the fungal-specific markers. For the studies of the photobiont guilds we will intensively sample species rich Lobariacean communities where several lichen species with different dispersal strategies that share the Dictyochloropsis photobiont guild grow together. This project will thus contribute to the understanding of evolutionary and population biological processes in lichens. The scientific innovation from this project is fourfold:(1) This is the first study covering the whole distribution range of a widely distributed lichen photobiont. It also aims to resolve the phylogenetic placement of several taxa of Dictyochloropsis; (2) Because L. pulmonaria and its photobiont D. reticulata are the only lichen-forming symbionts for which highly variable microsatellite markers are available, we will provide a first detailed co-phylogeography of a lichen symbiosis. The combination of the two marker sets will allow a detailed investigation of the dispersal range of both symbionts and their interdependence in structuring Lobariacean communities; (3) We will be able to test a crucial concept for understanding the establishment and maintenance of macrolichen communities, such as “the photobiont-mediated guild” involving several representatives of the family Lobariaceae both with sexual and vegetative dispersal strategies. These studies will shed new light on the importance of ecological processes such as dispersal, resynthesis and algal sharing in natural lichen communities; (4) Because Lobariacean species are often related to old-growth forest structures and are widely used as indicators of ecological continuity in conservation practice, this work will contribute to the development of the concept of co-evolutionarily significant units and thus provide an important innovation for global conservation priorities in lichens.