An Improved Screening Method for Evaluation of Resistance to Phytophthora Blight in Sesame Cultivars and Accessions

Phytophthora blight causes serious yield losses and deterioration of quality in sesame. In this study, we modified the screening method for enhancing the evaluation efficiency of Phytophthora blight resistance. The inoculum density and seedling stage were adjusted for large-scale screening. The optimal stage for inoculation was the seedlings grown to emerged-first-true leaves. At the density of 1 × 10⁴ to 1 × 10⁵ zoospores per milliliter, susceptible cultivars showed disease response within seven days. To verify the screening method, we assessed sesame cultivars and accessions for Phytophthora blight resistance, and varied resistance levels such as resistant, moderate and susceptible reactions were observed.