Abstract
Effects of tomato-juice and KH$_2$PO$_4$ as exogenous nutrients on the infection of Botrytis cinerea LVF12 and pathogenicity to tomato were investigated. B. cinerea LVF12, which was previously reported as a casual agent of the gray mold rot of perilla, was used for pathogenesis on tomato leaves. No infection was induced, and no lesion developed on tomato leaves by the conidial suspension of LVF12 when the inoculum was prepared in sterilized water. However, when the conidial suspensions of LVF12 added with various concentrations and conditions of tomato-juice were inoculated on whole tomato plants, the disease was induced readily, Among them, 20% tomato juice with 0.1M KH$_2$PO$_4$ appeared to be the most suitable nutrient to promote high disease incidence on tomato. For the pathogenicity test according to the growing stage of tomato, the mature leaves were more susceptible than seedlings. Symptoms on the infected plants were initial small gray spots at the inoculated area. Later the whole leaves, petioles and stems became gray and eventually fell off, Under high humidity conditions, the diseased leaves and stems were covered with gray hyphae and conidia. All symptoms of infected plants were identical to those in the field conditions.
잿빛곰팡이병균 Botrytis cinerea LVF12 분생포자의 토마토 잎 감염에 미치는 영양원의 영향을 조사하고 병원성을 검정한 결과, 0.1M KH$_2$PO$_4$를 첨가한 20% 토마토 쥬스로 만든 분생포자 부유액이 토마토 잎에서 일정하면서도 높은 발병도를 보여 감염에 효과적인 분생포자 영양원으로 선발하였다. 또한 토마토의 생육 단계별로 병원성을 검정한 결과, 유묘보다 성숙한 식물일수록 발병도가 높았고 하위엽이 상위엽보다 발병도가 높았다. 병징은 감염 초기에 갈색의 소형 점무늬가 잎에 형성되고 병반이 잎자루와 줄기까지 진전되면서 잎이 탈락하거나 줄기 전체가 갈변하여 고사하였다. 감염된 열매는 초기에 암갈색의 원형 병반이 형성되고 점점 진전되면서 열매가 물러 썩었는데, 습도가 높을 때에는 병든 잎, 줄기 및 열매가 잿빛의 균사와 분생포자로 뒤덮혀 자연 발생된 병징과 동일한 특성을 보여 주었다.
