Figure 1.
Wheat leaves were sampled in two important agricultural production areas of Sweden.
Dots represent position of individual fields within in the two sampling areas. The Northern sampling area (N) is located in the Västergötland region and the Southern area (S) in the Skåne region.
Table 1.
Distribution of wheat leaf samples between two geographical areas, fields and treatments, including weather data.
Figure 2.
Rarefaction and species accumulation curves.
a) Rarefaction curves presenting the relationship between sequencing depth and species richness in operational taxonomic units (OTUs). Error bars indicate 95% confidence intervals. b) Sample-based species accumulation curves. When more than two samples were taken per field, one fungicide-treated and one untreated sample was randomly chosen from each field for inclusion in the analysis. Error bars indicate 95% confidence intervals, only shown for Northern and Southern area respectively.
Figure 3.
Fungal community composition on wheat leaves at the order level.
Community composition is presented for the total dataset, fungicide-treated, control and samples from the Northern and Southern area respectively. Orders with low abundance have been merged to the group ‘Others’ to improve visual representation.
Table 2.
Taxonomic and functional assignment of the 30 most abundant operational taxonomic units (OTUs).
Figure 4.
Non-metric multidimensional scaling (NMDS) of phyllosphere fungal communities of wheat.
Ordination of samples with fitted environmental variables. Ellipses represent 95% confidence areas for Southern area (solid grey line), Northern area (solid black line), fungicide-treated (dashed grey line) and control (dashed black line) groups respectively. The NMDS was performed on the mean of 1000 rarefied datasets.
Figure 5.
Richness of operational taxonomic units (OTUs) and community evenness.
Boxplots with interquartile ranges of a) OTU richness and b) community evenness grouped by treatment (fungicide-treated and control samples) and geographical area. Horizontal lines represent medians and dots mean values. Samples from fields infected with yellow rust (Puccinia striiformis) in the Southern area (fields 15 and 16, Table S1) have been removed.
Table 3.
Effect of environmental and management factors on fungal community composition in the wheat phyllosphere.
Table 4.
Summary of the linear mixed model analysis of OTU richness and evenness.
Figure 6.
Distribution of community abundance for the most abundant OTUs grouped by treatment.
Boxplots with interquartile ranges showing the relative abundances of the 21 most abundant operational taxonomic units (OTUs) in the dataset grouped by treatment. Outliers are not shown, OTU_1_Puccinia_striiformis is therefore excluded. Significant (p<0.05) differences are marked with an asterisk.
Figure 7.
Distribution of community abundance for the most abundant OTUs grouped by geographical area.
Boxplots with interquartile ranges showing the relative abundances of the 21 most abundant operational taxonomic units (OTUs) in the dataset grouped by geographical area. Outliers are not shown, OTU_1_Puccinia_striiformis is therefore excluded. Significant differences (p<0.05) are marked with an asterisk.