Changes in the root‐associated fungal communities along a primary succession gradient analysed by 454 pyrosequencing

Abstract

We investigated changes in the root-associated fungal communities associated with the ectomycorrhizal herb Bistorta vivipara along a primary succession gradient using 454 amplicon sequencing. Our main objective was to assess the degree of variation in fungal richness and community composition as vegetation cover increases along the chronosequence. Sixty root systems of B. vivipara were sampled in vegetation zones delimited by dated moraines in front of a retreating glacier in Norway. We extracted DNA from rinsed root systems, amplified the ITS1 region using fungal-specific primers and analysed the amplicons using 454 sequencing. Between 437 and 5063 sequences were obtained from each root system. Clustering analyses using a 98.5% sequence similarity cut-off yielded a total of 470 operational taxonomic units (OTUs), excluding singletons. Between eight and 41 fungal OTUs were detected within each root system. Already in the first stage of succession, a high fungal diversity was present in the B. vivipara root systems. Total number of OTUs increased significantly along the gradient towards climax vegetation, but the average number of OTUs per root system stayed unchanged. There was a high patchiness in distribution of fungal OTUs across root systems, indicating that stochastic processes to a large extent structure the fungal communities. However, time since deglaciation had impact on the fungal community structure, as a systematic shift in the community composition was observed along the chronosequence. Ectomycorrhizal basidiomycetes were the dominant fungi in the roots of B. vivipara, when it comes to both number of OTUs and number of sequences.

Ecological succession reveals potential signatures of marine–terrestrial transition in salt marsh fungal communities

“…In contrast to other studies (see, for example, Blaalid et al, 2012;Brown and Jumpponen, 2014), we did not observe a clear directional shift in the fungal communities across successional stages. This was mostly because of the extreme abundance of the OTU affiliated with M. anisopliae at stage 35, which may indicate a high abundance of either the hyphal or spore forms.…”

“…Understanding fungal community turnover at local and regional scales is critical to explain ecological succession Microbial ecologists have only recently started to investigate the patterns of microbial community dynamics in natural systems (see, for example, Nemergut et al, 2007;Blaalid et al, 2012;Brown and Jumpponen, 2014;Dini-Andreote et al, 2014). As changes in microbial community composition are often associated with variations in the functional capabilities of the communities (Fierer et al, 2007;Salles et al, 2009), unravelling the temporal turnover patterns is crucial for understanding ecosystem processes.…”

Enigmatic Sebacinales

“…In plants of the Tyrolean Rotmoos glacier forefront, , and in the Bavarian Alps, Garnica et al (2012) found S. incrustans and several unnamed species of Sebacinales as ECM fungi in B. vivipara. Changes in the root-associated fungal communities along a primary succession gradient, analyzed by 454 pyrosequencing, has shown Basidiomycota, including Sebacina, as the dominant fungi by the numbers of OTUs and sequences (Blaalid et al 2012). Tremelloscypha gelatinosa has been reported for the first time from Yucatan, Mexico by Guzman (2004).…”

Effects of straw amendment and moisture on microbial communities in Chinese fluvo-aquic soil

“…The PLFA method has some misuse or misinterpretation to the specificity of signature PLFA and to what extent such PLFA are found in living microorganisms (Frostegård et al 2011). 18S rRNA genes are known to be too conserved to provide good separation of fungal taxa, and fungal-specific taxa should use the primers of ITS region of rRNA genes (e.g., Blaalid et al 2012;Xu et al 2012;Clemmensen et al 2013). Hence, more scientific methods will be applied in further research to make more accurate identification of microbial taxa.…”