Colour-analyzer: a new dual colour model-based imaging tool to quantify plant disease.

Abstract

Abstract Background Despite major efforts over the last decades, the rising demands of the growing global population makes it of paramount importance to increase crop yields and reduce losses caused by plant pathogens. One way to tackle this is to screen novel resistant genotypes and immunity-inducing agents, which must be conducted in a high-throughput manner. Results Colour-analyzer is a free web-based tool that can be used to rapidly measure the formation of lesions on leaves. Pixel colour values are often used to distinguish infected from healthy tissues. Some programs employ colour models, such as RGB, HSV or L*a*b*. Colour-analyzer uses two colour models, utilizing both HSV ( Hue, Saturation, Value ) and L*a*b* values. We found that the a* b* values of the L*a*b* colour model provided the clearest distinction between infected and healthy tissue, while the H and S channels were best to distinguish the leaf area from the background. Conclusion By combining the a* and b* channels to determine the lesion area, while using the H and S channels to determine the leaf area, Colour-analyzer provides highly accurate information on the size of the lesion as well as the percentage of infected tissue in a high throughput manner and can accelerate the plant immunity research field.

Plant phenotyping relevance

植物病斑面積と感染組織割合を画像から定量するウェブツールの開発であり、植物病害状態の表現型取得が中心的な貢献である。

Code and data availability

The paper's authors publicly released both the Colour-analyzer web tool/code on GitHub and the datasets generated in the study, hosted in a publications subfolder of the same repository. Both are paper-specific, public, and actionable.