Figure 4. BioClay^™ application provides a steady inhibition of Botrytis cinerea infection on tomato fruit.

(A) Tomato fruit were treated with water, naked dsRNA, LDH or BioClay and were then inoculated with B. cinerea spores 1, 5, or 10 d post treatment (dpt). Pictures were taken at 6 d post inoculation. Representative inoculated tomato fruit showed similar lesion sizes in the water control treatment, LDH treatment, CMV treatment (naked or BioClay) and both BcDCL1/2- and BcVDS naked dsRNA treatments at the last time point (10 dpt). Smaller lesion sizes were observed at all time points with BioClay treatments (either BcDCL1/2 or BcVDS) and at 1 dpt in the naked dsRNA treatments. (B) Relative lesion size areas were measured 6 d post inoculation on tomato fruits with the help of an electronic calibrator, assigning a value of 1.0 to the average lesion size area in the water treatment. (C) Relative fungal biomass was quantified by reverse transcription quantitative polymerase chain reaction (RT-qPCR) in tomato fruits inoculated with B. cinerea. Fungal RNA relative to tomato RNA was measured with the fungal actin gene and the tomato tubulin gene by RT-qPCR using total RNA extracted from each time point (1, 5, 10 dpt). All measurements were referred to the value 1.0 obtained for the water treatment. Error bars indicate standard deviations (SD) obtained of at least three biological replicates. Levels of significant differences were determined by a one-way analysis of variance followed by Tukey’s HSD test and are indicated above the bars by (⁰P < 0.10; *P < 0.05; **P < 0.01; ***P < 0.001).