First Record of Raffaelea promiscua Associated with Ambrosia Beetles in Korea

초록

In the present study, we isolated a fungus from an ambrosia beetle collected from a trap in an apple orchard in Gunwi-gun, Daegu, South Korea. The isolate was designated as ARI-25-A11. To classify the strain at a species level, both morphological and molecular analyses were conducted, and its phylogenetic position was determined. For cultural characterization, ARI-25-A11 was cultured on 2% malt extract agar at 25°C for 10 days, resulting in a colony diameter of 30.4–32.9 mm. White mycelium was observed at the center, and as the incubation period progressed, the center gradually darkened from olive to brown. Morphologically, the conidiophores were mononematous, septate, and hyaline, whereas the conidia were aseptate, predominantly oval, with an enlarged upper part and a tapered base, measuring an average of 5.9 × 3.5 µm. For molecular identification, the large subunit ribosomal RNA (LSU), small subunit ribosomal RNA (SSU), and β-tubulin (β-tub) genes were amplified and sequenced. The LSU and SSU sequences showed 100% identity with those of Raffaelea promiscua PL1001, and the β-tub gene sequence completely matched that of both R. promiscua PL1001 and CMW55899T. Phylogenetic analysis identified ARI-25-A11 within the same clade as R. promiscua. Based on morphological and molecular data, ARI-25-A11 was identified as R. promiscua, representing the first report of this species among ambrosia beetles in Korea.

키워드