양액 재배에 의한 배추 뿌리혹병 대량 접종법 개발

The Chinese cabbage (Brassica rapa L.) is one of the major vegetables in Korea that has been traditionally used as main ingredients of ‘Kimchi’. The cultivation system and varieties of Chinese cabbage have been so well developed that year-round culture using bare land is possible in Korea. However, the soil-born clubroot restricts cultivation of Chinese cabbage in the whole country. It caused root swelling and severe leaf wilting which reducing production of Chinese cabbage in Korea. To develop resistant varieties, breeders have to inoculate clubroot in their numerous breeding lines. However, current inoculation method demands much labor and time for investigation and sterilization. In order to solve the problems, we tried to develop a new method of soil-less inoculation method of clubroot using plug tray, urethane sponge as matrix and nutrient solution as media. Using this method, we successfully induced a typical symptom of clubroot after 8 weeks of hydroponic culture. The Russian accession showed less than 45% of resistance ratio and 3 collected varieties showed resistance ratio over 61%. We successfully induced the clubroot symptoms while reducing the amount of inoculums and labor required for the investigation and sterilization. This system can be used in clubroot resistant breeding program by screening numerous off-springs and germplasms of Brassica plants.