Anthracnose of Pomegranate Caused by Colletotrichum acutatum in Korea

Colletotrichum acutatum에 의한 석류나무 탄저병

Anthracnose of pomegranate (Punica granatum) caused by Colletotrichum acutatum was observed in the exhibition field at Hamyang-gun, Gyeongsangnam-do Agricultural Research and Extension Services, and in farmer's orchard at Gaheo-myon, Hapcheon-gun, Gyeongnam province, Korea. The pathogen generally attacks on the fruits and induces dark lesion and rotting. The infected fruits were mostly dropped or mummified. The color of colonies of the pathogenic fungus grown on potato dextrose agar was pinkish gray. Conidia were fusiform in shape and was $8{\sim}16{\times}3{\sim}4{\mu}m$ in size. Appressoria were pale to dark brown in color, clavate in shape and was $8{\sim}12{\times}4{\sim}6{\mu}m$ in size. Optimum temperature for mycelial growth was $25^{\circ}C$. Pathogenicity of the causal organism was proved according to Koch's postulate. On the basis of mycological characteristics and pathogenicity test on fruit, the fungus was identified as Colletotrichum acutatum. This is the first report on the anthracnose of pomegranate caused by C. acutatum in Korea.

2004년부터 2005년까지 경남농업기술원 약초연구팀과 합천군 가회면 농가포장에서 석류나무 과실이 심하게 부패되는 증상이 발생하였다. 병징은 과실의 끝부분이 갈색 또는 암갈색의 수침상으로 썩는다. 균총의 색깔은 감자한 천배지에서 회색이며 배지표면에 분홍색의 분생포자퇴를 형성하였다. 분생포자의 모양은 단세포, 방추형이며, 크기는 $8{\sim}16{\times}3{\sim}4{\mu}m$ 이었다. 부착기는 연한 암갈색이고 곤봉 상이며 크기는 $8{\sim}12{\times}4{\sim}6{\mu}m$ 이었다. 균사생육 적온은 $25^{\circ}C$였으며 유상접종에서 병원성이 잘 발현되었다. 이상의 결과로 보아, 이 병원균을 Colletotrichum acutatum에 의한 석류나무 탄저병으로 명명할 것을 제안한다.