Data from: Population structure of mountain pine beetle symbiont Leptographium longiclavatum and the implication on the multipartite beetle-fungi relationships

Over 18 million ha of forests have been destroyed in the past decade in
Canada by the mountain pine beetle (MPB) and its fungal symbionts.
Understanding their population dynamics is critical to improving modeling
of beetle epidemics and providing potential clues to predict population
expansion. Leptographium longiclavatum and Grosmannia clavigera are fungal
symbionts of MPB that aid the beetle to colonize and kill their pine
hosts. We investigated the genetic structure and demographic expansion of
L. longiclavatum in populations established within the historic
distribution range and in the newly colonized regions. We identified three
genetic clusters/populations that coincide with independent geographic
locations. The genetic profiles of the recently established populations in
northern British Columbia (BC) and Alberta suggest that they originated
from central and southern BC. Approximate Bayesian Computation supports
the scenario that this recent expansion represents an admixture of
individuals originating from BC and the Rocky Mountains. Highly
significant correlations were found among genetic distance matrices of L.
longiclavatum, G. clavigera, and MPB. This highlights the concordance of
demographic processes in these interacting organisms sharing a highly
specialized niche and supports the hypothesis of long-term multipartite
beetle-fungus co-evolutionary history and mutualistic relationships.