Ecological specialization in Trebouxia (Trebouxiophyceae) photobionts of Ramalina menziesii (Ramalinaceae) across six range‐covering ecoregions of western North America1. Issue 7 (1st July 2014)

• Record Type: Journal Article
• Authors: Werth, Silke; Sork, Victoria L.
• Is Part Of: American journal of botany. Volume 101:Issue 7(2014)
• Page Start: 1127
• Page End: 1140
• Publication Date: 2014-07-01
• Subjects: ecological specialization -- genetic differentiation -- host plant specificity -- lichenized ascomycetes -- phorophyte -- photobiont -- Ramalina menziesii -- Ramalinaceae -- symbiosis -- Trebouxia decolorans -- Trebouxiophyceae; Botany -- Periodicals; Botany; Electronic journals; Periodicals; 580
• DOI: 10.3732/ajb.1400025
• Languages: English
• ISSNs: 0002-9122

Abstract

Abstract : Premise of the study: Many lichens exhibit extensive ranges spanning several ecoregions. It has been hypothesized that this wide ecological amplitude is facilitated by fungal association with locally adapted photobiont strains. Methods: We studied the identity and geographic distribution of photobionts of the widely distributed North American lichen Ramalina menziesii based on rbcL (chloroplast DNA) and nuclear ribosomal ITS DNA sequences. To test for ecological specialization, we associate photobiont genotypes with local climate and phorophyte. Key results: Of the photobiont lineages of R. menziesii, 94% belong to a clade including Trebouxia decolorans . The remaining are related to T. jamesii . The photobionts showed (1) significant structure according to ecoregion and phorophyte species and (2) genetic associations with phorophyte species and climate. Conclusions: Geography, climate, and ecological specialization shape genetic differentiation of lichen photobionts. One great advantage of independent dispersal of the fungus is symbiotic association with locally adapted photobiont strains.