Analysis of fungal endophytes in Scottish Sitka spruce plantations shows extensive infections, novel host partners and gives insights into origins

Abstract

This preliminary study identified the fungal endophytes of Sitka spruce (Picea sitchensis) in four Scottish plantations, analysed their recruitment possibilities and community structure across the sites, and identified the possible origins of the endophytes in this non‐native host. Although Sitka spruce is native to north‐western North America, it comprises a huge portion of Scottish forestry and is an economically vital timber tree. Needles from two age classes were collected and cultured for emerging endophyte isolates. Using a combination of morphological features and genetic sequencing of the nuclear ribosomal ITS regions of representative morphological types, 57 morphotypes were recorded which represented at least 15 different species, including a hypothesized sister species to the pathogen of Pseudotsuga menziesii in North America and Europe, Nothophaeocryptopus gaeumannii (previously P. gaeumannii) that was present at all sites tested. Diversity, recruitment, site, needle age and needle part effects are discussed. The phylogeny of Nothophaeocryptopus based on analysis of combined ITS and Tub2 sequence data is given in order to assess the relationship of the unknown endophyte to the Douglas fir pathogen N. gaeumannii.

Mollisiaceae: An overlooked lineage of diverse endophytes

“…While generally considered to be “just” saprotrophs, some studies also report Mollisia as endophytes of leaves and twigs in diverse host plants ( Sieber, 1989 , Barklund and Kowalski, 1996 , Shamoun and Sieber, 2000 , Kowalski and Andruch, 2012 , Anderson Stewart et al. 2019 , Lee et al.…”

Towards resolvingNothophaeocryptopusandRhizosphaerainhabitants of spruce needles

“…Needle litter samples were collected at each sampling time, whereas living green needles for endophytic fungi were only sampled in Scotland in Nov 2017 and in Wales in May 2018. Sitka spruce had been previously sampled for endophytic fungi in May (2015) in Scotland (Anderson‐Stewart et al, 2018) therefore only a sub‐sample of the hosts was tested in May 2018 to confirm the findings of the previous November. The sites in Wales were sampled only once due to difficulties in arranging access to sites in October 2017.…”

“…There are only a few studies in the UK where Sitka spruce is an exotic, non‐native tree (Anderson‐Stewart et al, 2018; Magan et al, 1995; Magan & Smith, 1996); and one in the native range of Sitka spruce in the northwest of North America (Carroll & Carroll, 1978). The question of the origin of endophytes in a non‐native conifer in the UK was discussed by Anderson‐Stewart et al (2018) for Sitka spruce but with inconclusive results. The most abundant members of the endophyte community sampled in the study by Anderson‐Stewart et al (2018) were two species: Lophodermium piceae (Fuckel) Höhn.…”

“…aff. gaeumannii has not been treated in detail (Anderson‐Stewart et al, 2018). Additionally, in their study, Anderson‐Stewart et al (2018) isolated endophytes that are considered to have broader host ranges such as strains of species belonging to the genus Diaporthe and members of the order Xylariales .…”

Eradication of endophytes from needles, their inoculation with Lophodermium piceae and persistence of this fungus in needles of Norway spruce

“…is the most common needle endophyte of Norway spruce needles constituting generally more than 90% of endophytic isolates obtained from the needles (Sieber, 1988;Müller and Hallaskela 1998). L. piceae has been found also in needles of Abies alba (Gourbière 1988;Minter 1994) and needles of Scottish P. sitchensis (Stewart et al, 2019). This fungus probably occurs in the whole distribution area of Norway spruce throughout Eurasia (Müller et al, 2019).…”