Fungi in Roots of Nursery Grown Pinus sylvestris: Ectomycorrhizal Colonisation, Genetic Diversity and Spatial Distribution

Abstract

The aims of this study were to investigate patterns of ectomycorrhizal (ECM) colonisation and community structure on nursery grown seedlings of Pinus sylvestris, spatial distribution of ECMs in the nursery plot and genetic diversity of commonly isolated ECM basidiomycete Hebeloma cavipes. One hundred seedlings were sampled in 225 m(2) area using a systematic grid design. For each seedling, 20 individual root tips were randomly collected, morphotyped, and surface sterilised for fungal isolation in pure culture. Results showed that ECM community was comprised of nine distinct morphotypes among which Thelephora terrestris (39.7%), Hebeloma sp. (17.8%) and Suillus luteus (6.1%) were the most abundant. Spatial distribution of ECMs in the nursery plot was determined by their relative abundance: even in common ECMs and random in rare ones. Fungal isolation yielded 606 pure cultures, representing 71 distinct taxa. The most commonly isolated fungi were the ascomycetes Neonectria macrodidyma (20.3%), Phialocephala fortinii (13.5%), Neonectria radicicola (6.3%) and the ECM basidiomycete H. cavipes (4.5%). Intraspecific genetic diversity within 27 H. cavipes isolates was studied using two methods: restriction digestion of the amplified intergenic spacer of nuclear ribosomal DNA and genealogical concordance of five genetic markers. Five and eight genotypes were revealed by each respective method, but both of those were largely consistent, in particular, in determining the largest genotype (A) composed of 18 isolates. Mapping positions for each H. cavipes isolate and genotype in the field showed that isolates of the A genotype covered a large part of the nursery plot. This suggests that H. cavipes is largely disseminated by vegetative means of local genotypes and that nursery cultivation practices are likely to contribute to the dissemination of this species in the forest nursery soils.

High-Throughput Sequencing Shows High Fungal Diversity and Community Segregation in the Rhizospheres of Container-Grown Conifer Seedlings

“…For example, Voříšková et al [41] demonstrated that, in a temperate oak forest soil saprotrophic genera reached their seasonal maxima in autumn, while mycorrhizal taxa dominated in summer, suggesting that decomposition of organic matter and phytosynthate allocation represent important factors contributing to the community variations during the growing season. Despite the high fungal diversity, fungal community was dominated by a limited number of fungal taxa (Table 2) many of which were reported from forest nurseries before [14,15,22,39,42]. Therefore, our results corroborate previous observations and demonstrate specificity of fungal communities in forest nurseries.…”

“…Early detection of such diseases is critical as this can prevent further establishment and spread to new environments. In addition to detrimental pathogenic fungi, roots of tree seedlings harbor beneficial communities of fungi [14,15], which may promote seedling growth both in forest nurseries and after outplanting [16]. Mycorrhizal fungi are known to provide nutritional benefits to their hosts and may increase tolerance to abiotic and biotic stress factors [17].…”

Diversity of ectomycorrhizal fungus assemblages on nursery grown European beech seedlings

“…Our findings add to the evidence of a growing number of symbionts being able to colonize seedlings in nursery conditions, and emphasize the elucidation potential of molecular tools for detailed descriptions of ECM communities in different environments. Some of the identified fungi (Cenococcum, Tuber, Hebeloma, Laccaria) have been previously noted in forest nurseries as ECM symbionts of coniferous (Menkis et al 2005;Rudawska et al 2006;Leski et al 2008;Menkis and Vasaitis 2011) or deciduous hosts (Leski et al 2010), but some of them have been found for the first time in nursery conditions (Hydnotrya, Hymenogaster, Lactarius), or even as mycorrhizal partners of European beech (Naucoria, Geopora). For more details about the detected ECM fungi, see Online Resource 3.…”

Survival, Growth and Mycorrhization of Containerised Pinus sylvestris and Picea abies Seedlings of Different Provenances Outplanted in a Forest Clear-Cut

“…For molecular identification of fungal taxa, 1-5 root tips of each distinct ECM morphotype per each seedling provenance were placed in 1.5 ml centrifugation tubes and stored at -16°C . DNA extraction and PCR using primers ITS1F and ITS4 (White et al, 1990) were conducted as in a previous study (Menkis and Vasaitis, 2011). Sequencing was performed by Macrogen Inc., Seoul, Korea and raw sequence data were analysed using the SeqMan Pro version 9.1.0 software from the DNASTAR package (DNASTAR, Madison, WI, USA).…”

“…However, intensive management practices (often fertilization, application of pesticides for weed and pest control, etc.) in forest nurseries may often result in both reduced ECM colonisation of seedling roots and species diversity (Nilsson and Wallander, 2003), and only a limited number of ECM fungi can tolerate such growth conditions (Menkis and Vasaitis, 2011). A number of studies have shown importance of host genotype to richness and abundance of ECM fungi associated with seedling roots (Korkama et al, 2006;Leski et al, 2010;Velmala et al, 2013), indicating that selection of particular tree genotype or seed provenance may improve ECM colonisation of seedling roots and eventually their better performance after outplanting.…”