Pseudoperonospora cubensis Causing Downy Mildew on Luffa aegyptiaca in Korea

Abstract

In November 2021, sponge gourd (Luffa aegyptiaca) plants with typical downy mildew symptom were observed in Korea. Based on morphological characteristics of sporangiophores and sporangia, combined with molecular phylogenetic analysis of the internal transcribed spacer rDNA and cox2 mtDNA regions, the causal pathogen was identified as Pseudoperonospora cubensis (Oomycota). This is the first report of downy mildew caused by P. cubensis on L. aegyptiaca in Korea. Given that P. cubensis exhibits high disease incidence and severity on many Cucurbitaceae crops, it could pose a significant threat to sponge gourd cultivation.

Keywords

• cucurbitaceae
• oomycota
• sponge gourd