Abstract
A disease causing blights on leaves, stems, flowers, and pods of Vinca (Catharanthus roseus L.) was occurred in Aug. 2003 in Chengdo Peach Experiment Station. A species of Phytophthora was isolated from the diseased tissues. The causal fungus was identified as Phytophthora nicotianae on the basis of mycological characteristics and pathogenicity. Sporangia were ovoid to spherical, noncaducous, prominently papillate and averaged 38.0${\times}$31.0 ${\mu}{\textrm}{m}$ in dimension. Chlamydospores were abundantly produced on agar media and sized about 30.5 fm in diameter, The fungus was heterothallic and Al mating type. Oospores were measured 23.1 ${\mu}{\textrm}{m}$ in size. Optimum temperature for growth of the fungus was 25 to 3$0^{\circ}C$. This is the first report of occurrence of foliage blight of Vinca caused by P. nicotianae in Korea.
2003년 8월 청도시험장의 화분재배한 일일초에서 잎, 꽃, 꼬투리 및 줄기가 검게 시들고 말라죽는 증상으로부터 병원균을 분리$.$동정한 결과 Phytophthora nicotianae로 동정되었다 병원균의 형태적 특성은 뚜렷한 유두돌기를 가지고 비탈락성인 원형 혹은 난형의 유주자낭을 형성하였고, 크기는 31.0${\times}$38.0$\mu\textrm{m}$였고 다량의 후막포자를 형성하였으며 크기는 평균 직경이 30.5 $\mu\textrm{m}$였다 유성생식형은 자웅이주로 Al mating type이 관찰되었고 난포자의 크기는 직경 23.1 $\mu\textrm{m}$였다. 균사의 생육적온은 25∼3$0^{\circ}C$였다. 이상과 같이 국내 최초의 P. nicorianae에 의한 일일초 역병의 발생을 보고하는 바이다.
