Biodiversity and molecular ecology of Russula and Lactarius in Alaska based on soil and sporocarp DNA sequences

Abstract

Although critical for the functioning of ecosystems, fungi are poorly known in highlatitude regions. This paper summarizes the results of the first genetic diversity assessments of Russula and Lactarius, two of the most diverse and abundant fungal genera in Alaska. SU rDNA sequences from both curated sporocarp collections and soil PCR clone libraries sampled in various types of boreal forests of Alaska were subjected to phylogenetic and statistical ecological analyses. Our diversity assessments suggest that the genus Russula and Lactarius are highly diverse in Alaska. Some of these taxa were identified to known species, while others either matched unidentified sequences in reference databases or belonged to novel, previously unsequenced groups. Taxa in both genera showed strong habitat preference to one of the two major forest types in the sampled regions (black spruce forests and birch-aspen-white spruce forests), as supported by statistical tests. Our results demonstrate high diversity and strong ecological partitioning in two important ectomycorrhizal genera within a relatively small geographic region, but with implications to the expansive boreal forests. The pronounced differences in community composition between various forest types are particularly relevant to climate change studies, as a diverse set of Russula and Lactarius species undoubtedly play an important role in the predicted expansion of deciduous forests in the boreal and low arctic regions.

Citation

J., Geml; Taylor, D.L. 2013. Biodiversity and molecular ecology of Russula and Lactarius in Alaska based on soil and sporocarp DNA sequences. Scripta Botanica Belgica. 51: 132-145.