Patterns of fungal diversity in needles, rootlets and soil of endemic Pinus peuce

Abstract

Pinus peuce is a five-needle pine native to high-elevation montane habitats of the Balkans. This study aimed to assess the diversity and composition of fungal communities associated with soil, rootlets and living needles of P. peuce at three high-altitude forest sites with different edaphic conditions and stand characteristics in south-eastern Montenegro. In total, 90 samples of each substrate (needles, rootlets and soil) were sampled. DNA amplification using ITS2 rDNA as a marker and high-throughput sequencing resulted in 23,394 high-quality reads, representing 825 fungal taxa. There were 52.5% Basidiomycota, 43.9% Ascomycota and 3.6% Mucoromycotina. There were 118 unique fungal taxa in the rootlets, 230 in soil and 113 in the needles, and only 8 taxa were shared. The most common fungi in rootlets were Rhizopogon mohelensis (11.0%), Suillus americanus (8.4%), and R. fallax (6.9%), in soil – Phlebiopsis gigantea (5.1%), Tylospora asterophora (2.9%), and Sollicocossima terricola (2.7%), and in the needles – Dothideomycetes sp. (17.6%), Dothideomycetes sp. (10.7%), and Leotiomycetes sp. (6.5%). The results showed that functional tissues and the rhizosphere soil of P. peuce were inhabited by a  high diversity of fungi. Fungal communities in the rootlets and soil were largely determined by the site conditions such as  soil properties and forest stand composition.

Keywords: Pinus peuce, five needle pine, high-altitude forests, ectomycorrhiza, pathogens, saprotrophs, Montenegro