Horticultural Science and Technology 원예과학기술지 ISSN:1226-8763(Print) 2465-8588(Online)

Leaf blight caused by Stemphylium vesicarium is an important fungal disease of the Allium genus, which decreases the quality and seed yield of garlic (Allium sativum). To establish an efficient screening method for testing the resistance of garlic cultivars to S. vesicarium, we measured leaf blight development on garlic plants according to cultivar, plant growth stage, inoculum concentration, nutrient source contained in the spore suspension, and incubation temperature. We determined that the most efficient method to develop leaf blight on garlic plants involved the following procedures: First, garlic cloves were grown in horticultural soil and cultivated in a greenhouse (25 ± 5°C). Seedlings at the four-leaf stage were rubbed with bleached, nonabsorbent cotton and spray-inoculated with a spore suspension (3.0 × 10⁵ spores/mL) of the fungus composed of sterilized 1/2 potato dextrose broth. The inoculated plants were incubated in a dew chamber at 20°C for 48 hours, and then the infected seedlings were cultured in a growth chamber at 25°C and 80% RH under 12-hour light per day. Seven days after inoculation, infected leaf area (%) was measured. Our screening system can be used to select resistant resources and develop S. vesicarium-resistant garlic cultivars.