국내 사과탄저병균의 다양성 및 살균제 감수성 모니터링

다국어 초록 (Multilingual Abstract)

In Korea, apple bitter rot caused by diverse Colletotrichum species is managed primarily through fungicide applications, yet comprehensive fungicide monitoring data remain limited. We evaluated the sensitivity of Colletotrichum spp. causing apple bitter rot to four fungicides: benomyl, fluazinam, pyraclostrobin, and tebuconazole. From 2022 to 2024, we collected a total of 2,440 isolates from major apple-producing regions across five provinces in Korea. Among the four fungicides tested, fluazinam (86.8%) and tebuconazole (97.2%) maintained high sensitivity. Benomyl sensitivity was 54.3%, with a gradual decline from 56.7% in 2022 to 50.0% in 2024. Pyraclostrobin sensitivity was the lowest at 19.9%, with a marked increasing trend from 9.8% in 2022 to 28.6% in 2024. Isolates from Gangwon and Gyeonggi provinces were more sensitive to benomyl and pyraclostrobin than those from Jeolla Province. The dominant species were C. fructicola (46.7%) and C. siamense (40 .8%). Although C. siamense isolates exhibited relatively higher sensitivity to benomyl and pyraclostrobin than C. fructicola, 46.4% of C. siamense isolates showed moderate resistance to pyraclostrobin. Mutation analysis using KASP (Kompetitive Allele-Specific PCR) revealed that pyraclostrobin resistance was associated with the G143A mutation in the cytochrome b gene; however, this mutation was not detected in isolates showing moderate resistance. By elucidating annual sensitivity changes, regional distributions of dominant species, and interspecific differences among Colletotrichum isolates causing apple bitter rot in Korea, these findings provide essential baseline data for developing region-specific fungicide management strategies.