The Occurrence of Sooty Mold of Blueberry Caused by Cladosporium sphaerospermum in Korea

Abstract

In March of 2015, severe sooty mold was observed on blueberries cultivated in a farmer’sgreenhouses in Goseong-gun, Gyeongsangnam-do, South Korea. Typical symptoms included ablack or dark brown, superficial fungal growth on the leaves, stems, and fruit of blueberryplants. The fungal colonies on PDA were flat and black. The conidia were dark green in color,globose to sub-globose in shape and 3-5×3-4 μm in size. The ramoconidia were cylindrical and18-42×3 μm in size. The conidiophores were dark brown, cylindrical-oblong in shape and42-138×3-4 μm in size. To confirm the identity of the fungus(F130), the 18S rDNA as well asactin and β-tubulin gene sequences were PCR-amplified and sequenced. The pathogenicity ofthe isolate was then explored on 2-month-old potted blueberry plants. Based on the mycologicalcharacteristics, molecular identification, and pathogenicity on host plants, this fungus wasidentified as Cladosporium sphaerospermum. This is the first report on sooty mold of blueberrycaused by C. sphaerospermum in Korea.