생물검정을 이용한 딸기(Fragaria×ananassa Duch.) 유전자원의 역병균(Phytophthora cactorum)에 의한 crown rot 저항성 평가

Crown rot caused by Phytophthora cactorum is one of several serious, widespread diseases that cause problems in strawberry (Fragaria × ananassa Duch.) cultivation. In this study, we aimed to identify a strawberry resistant to P. cactorum through bioassay. A total of 104 wild and cultivated strawberry accessions, including ‘Sulhyang’ and ‘Akihime’, were inoculated with an isolate of P. cactorum, ‘PC151111’. A zoospore suspension was used with a density of approximately 106 zoospores·mL-1. Three strawberry seedlings were tested three times independently. The disease index was scored on a scale from 0–4 through symptom observation while the inoculated plants were incubated at 25±3°C under 16 h/8 h (light/dark) conditions for three weeks. The results showed that the mean disease index varied from 0.78–3.78, and the ‘Pechika’ and ‘Kaorino’ cultivars were highly resistant to P. cactorum, with mean disease indexes of 0.78 and 0.89, respectively. These cultivars will be useful resources in breeding strawberries resistant to crown rot.