Comparing Visual and Image Analysis Techniques to Quantify Fusarium Basal Rot Severity in Mature Onion Bulbs

Development of resistant cultivars for Fusarium basal rot (FBR), a fungal disease caused by the soil-borne fungus oxysporum f.sp. cepae (FOC), is major breeding goal onion programs around world. Currently, selection FBR-resistant bulbs based on visual interval or category scale, which an entirely subjective method. This study aimed to develop objective approach using digital image analysis quantify symptom development in plate dormant bulbs. Digital analyses were performed after artificially inoculating eighty-five United States Department Agriculture (USDA) Allium cepa accessions with virulent FOC isolate, ‘CSC-515’. An confocal microscopy identified bright blue–green autofluorescence from FOC-infected tissue, effectively differentiating diseased healthy tissue. Visual scoring FBR was aided stereo fluorescence microscopic images captured green protein dual filter accurately severity automatic stepwise segmentation method developed that relatively more accurate than estimation. exhibited comparable reliability and precision scoring, but it tended underestimate infection. To our best knowledge, this first comprehensive investigate potential use as viable alternative conventional development. could be used developing near future.