Assessing Performance of Spore Samplers in Monitoring Aeromycobiota and Fungal Plant Pathogen Diversity in Canada

Abstract

Spore samplers are widely used in pathogen surveillance but not so much for monitoring the composition of aeromycobiota. In Canada, a nationwide spore-sampling network (AeroNet) was established as a pilot project to assess fungal community composition in air and rain samples collected using three different spore samplers in the summers of 2010 and 2011. Metabarcodes of the internal transcribed spacer (ITS) were exhaustively characterized for three of the network sites, in British Columbia (BC), Québec (QC), and Prince Edward Island (PEI), to compare performance of the samplers. Sampler type accounted for ca. 20% of the total explainable variance in aeromycobiota compositional heterogeneity, with air samplers recovering more Ascomycota and rain samplers recovering more Basidiomycota. Spore samplers showed different abilities to collect 27 fungal genera that are plant pathogens. For instance, Cladosporium spp., Drechslera spp., and Entyloma spp. were collected mainly by air samplers, while Fusarium spp., Microdochium spp., and Ustilago spp. were recovered more frequently with rain samplers. The diversity and abundance of some fungi were significantly affected by sampling location and time (e.g., Alternaria and Bipolaris) and weather conditions (e.g., Mycocentrospora and Leptosphaeria), and depended on using ITS1 or ITS2 as the barcoding region (e.g., Epicoccum and Botrytis). The observation that Canada's aeromycobiota diversity correlates with cooler, wetter conditions and northward wind requires support from more long-term data sets. Our vision of the AeroNet network, combined with high-throughput sequencing (HTS) and well-designed sampling strategies, may contribute significantly to a national biovigilance network for protecting plants of agricultural and economic importance in Canada.IMPORTANCE The current study compared the performance of spore samplers for collecting broad-spectrum air- and rain-borne fungal pathogens using a metabarcoding approach. The results provided a thorough characterization of the aeromycobiota in the coastal regions of Canada in relation to the influence of climatic factors. This study lays the methodological basis to eventually develop knowledge-based guidance on pest surveillance by assisting in the selection of appropriate spore samplers.

Geographical Distribution of Fungal Plant Pathogens in Dust Across the United States

“…org/10.6084/m9.figshare.1270900), although this fungus has been isolated specially in tropical areas (Batta, 2004). However, we acknowledge that this study represents a simple snapshot of the fungal plant pathogen inocula in settled dust and these patterns might not reflect seasonal dynamics (Chen et al, 2018). We found some other cases of pathogen geographical distributions completely mismatched that of their potential hosts.…”

“…The most abundant and widespread fungal plant pathogens in settled dust across the US were ubiquitous, opportunistic, airborne, and stress-adaptable species such as Cladosporium sphaerospermum, Alternaria alternate, and Aureobasidium pullulans (Gonzalez-Martin et al, 2014). However, we acknowledge that passively collected dust alone might not recover the complete diversity of fungal plant pathogen inocula as different sampler types differ in their collection potential (Chen et al, 2018). Cladosporium sphaerospermum is a cosmopolitan saprotroph and secondary colonizer of dead or dying plant tissue that frequently dwells in nutrient poor environments like dust (Zalar et al, 2007).…”

Combined Metabarcoding and Co-occurrence Network Analysis to Profile the Bacterial, Fungal and Fusarium Communities and Their Interactions in Maize Stalks

“…Only OTUs assigned to kingdom Fungi were used for further analysis. The taxonomy for fungi known to have both sexual and asexual stages was replaced by accepted names according to Chen et al (2018).…”

Reproduction and Dispersal of Biological Soil Crust Organisms

“…Efforts to detect and identify airborne mycorrhizal propagules is often difficult and tends to under-report some fungal taxa. The use of molecular approaches such as DNA metabarcoding, however, can uncover fungal diversity missed by traditional morphological techniques including microscopy (Pashley et al, 2012;Chen et al, 2018), thus providing a more comprehensive estimate of fungal diversity in aerial samples (Banchi et al, 2018).…”