Genetic Structure of Lobaria pulmonaria in the Alps as a Result of Post-Glacial Recolonization History

Abstract

Lerch M., Nadyeina O. & Scheidegger C. 2018: Genetic structure of Lobaria pulmonaria in the Alps as a result of post-glacial recolonization history. – Herzogia 31: 650 – 665.The present-day genetic structure of a species is highly influenced by its history. Quaternary range expansions and contractions had a major impact on the genetic diversity and structure of species, which has implications for presentday conservation strategies of rare and threatened species. The aim of this study was to investigate the genetic structure of Lobaria pulmonaria and its green-algal photobiont Symbiochloris reticulata from the Alps. Here we present the genetic structure of 75 Lobaria pulmonaria populations and we investigated which of three fungal and two algal genetic lineages that were recognized in a broader study on the European phylogeography of this species are present in the Alps and from where postglacial recolonization might have occurred. Our study showed that only the fungal genepool A and the algal genepool R contributed to the recolonization of the Alps. The fungal genepools B1 and B2 were restricted to the eastern and western borders of the Alps but play an important role in the current populations in the Jura Mountains, the Vosges and the Black Forest. The algal genepool S was only found at the southwestern borders of the Alps and we hypothesize that this genepool is adapted to Mediterranean climates. For both symbionts we found a significant positive correlation between longitude and allelic richness, indicating a recolonization of the Alps from a peripheral refugium for genepool A at the eastern border of the Alps or from the Carpathian Mountains.