Abstract
Fusarium head blight (FHB) caused by Fusarium pathogens is a globally important cereal disease. To study Fusarium pathogenicity and host disease resistance, robust methods for disease assessment and quantification are needed. Here we describe the procedure of a detached leaves assay emphasizing the image analysis. The protocol provides the different steps of a rapid, automatic and quantitative image analysis to evaluate leaf area infected by Fusarium graminearum.
Keywords: Detached leaf assay, Disease assessment, Fusarium graminearum, Image analysis, Fiji, Pathogenicity, Wheat
Background
Evaluation of wheat FHB resistance at the whole plant level is estimated by visual scoring at flowering stage which is laborious, time consuming and requires space. Therefore in vitro methods that expedites disease assessment for FHB resistance at early plant stage have been developed, such as seed germination assay (Browne, 2009), coleoptiles assay (Shin et al., 2014), detached leaf assay (Browne and Cooke, 2004) and seedling assay (Li et al., 2010). Detached leaves assay is commonly used to assess host responses to Fusarium and was successful in identifying components of FHB resistance (Browne and Cooke, 2004). In such assays pathogen establishment is visually assessed which is time-consuming and limits accurate measurement. The method described recently by Perochon et al. (2015) and detailed here resolved these two limitations by using an automatic method that quantifies leaf area infected by image analysis based on particle size.
Materials and Reagents
Equipment
Software
Procedure
Data analysis
Notes
Acknowledgments
This work was supported by the Science Foundation Ireland (project Nos. 10/IN.1/B3028 and 14/1A/2508). Parts of this protocol were adapted from previously described detached leaf disease experiments (Browne and Cooke, 2004; Perochon et al., 2015). The authors thank Pierre Grandjean for technical assistance and Emmanuel G. Reynaud (UCD) for assistance with image analysis.
References
If you have any questions/comments about this protocol, you are highly recommended to post here. We will invite the authors of this protocol as well as some of its users to address your questions/comments. To make it easier for them to help you, you are encouraged to post your data including images for the troubleshooting.