Trypan blue staining is a classic way of visualizing leaf disease and wound responses in plants, but it involves working with toxic chemicals and is time-consuming (2-3 days). Here, the investigators established near-infrared scanning with standard lab equipment as a fast and nondestructive method for the analysis of leaf injuries compared with trypan blue staining. Pathogen-inoculated and wounded leaves from potato, tomato, spinach, strawberry, and arabidopsis plants were used for proof of concept. The results showed that this newly developed protocol with near-infrared scanning gave the same results as trypan blue staining. Furthermore, a macro in FIJI was made to quantify the leaf damage. The new protocol was time-efficient, nondestructive, chemical-free and may be used for high-throughput studies.
Keywords: Phytophthora; image processing; leaf damage; lesions; phenotyping; plant disease; potato.