Fig. 2
L. maculans fungal biomass assays of, and progression in, 9 and 12 dpi cotyledons (Experiment 2). A ddPCR tests on DNA extracted from D2 infected cotyledons 9 dpi from canola cultivars in this study (P < 5 × 10–7). B Disease progression ddPCR results between 9 and 12 dpi timepoints (P < 1.5 × 10–8 at 12 dpi). Bar diagram A distinguishes cultivars Bn1, ATR-Mako and ATR-Bonito (referred to as Mako and Bonito respectively) from each other and all from susceptible Westar at 9 dpi—broken lines extending from diagrams A, B indicate the breadth of scale in the progression shown in B. (Hyola350TT is referred to as Hyola). Standard error bars represent 14 biological replicates. C: Wheat germ agglutinin (WGA) chitin assay (WAC) performed on the respective 2nd cotyledons of the 12 dpi timepoint samples used for ddPCR (B). Relative fungal biomass assays indicate similar trends between 1st cotyledons subjected to ddPCR assays A, B and the WAC assay C respectively. Standard errors included in bar diagrams and progression diagram represent the mean from 14 biological replicates (P < 8 × 10–8). (ATR-Mako, ATR-Bonito, and Hyola®350TT cultivars are referred to as Mako, Bonito and Hyola, respectively). D Linear Regression test on the respective 12 dpi cotyledon WAC and ddPCR data set at confidence level of 95% obtained an adjusted R2 value of 0.9942 indicating a strong correlation between the results of the WAC and the ddPCR. Standard error bars for X- and Y-axes are shown for each mean data point, respectively. SE bars represent 14 biological replicates. E ddPCR results on the DNA extracted from the petiole samples removed from infected cotyledons which were sampled 9 dpi (data for 12 dpi not shown). Standard error bars represent 14 biological replicates (P < 0.061). (ATR-Mako, ATR-Bonito, and Hyola350TT cultivars are referred to as Mako, Bonito and Hyola, respectively). F Representative infected cotyledons sampled at 9 and 12 dpi respectively. G and H: Epifluoresence image of a WGA-TRITC stained ATR-Stingray cotyledon at 14 dpi. L.maculans hyphae spread (orange) from the inoculation points (G) and an enlargement of the yellow boxed region (H) showing hyphal growth in cells surrounding the vascular strand (blue) in petiole. Scale bars show 5 and 2 mm in G and H, respectively