Abstract
It was conducted to identify all 47 isolates obtained from infected fruits of pepper and boxthorn, and to investigate the mycological characteristics and the response to fungicides. All of 11 isolates from pepper were identified as Colletotrichum acutatum included into A2 group. Among 36 isolates from boxthorn, 14 isolates were identified as C. gloeosporioides, and the others were done as C. acutatum, which were composed as A1 group with 15 isolates and A3 with 7 isolates. After incubating the isolates on PDA at $25^{\circ}C$ for 10 days, the colony color of C. acutatum was greyish white, while that of C. gloeosporioides was orange at center of colony and was gradually turned into an greyish white to the periphery. The rate of conidia showing ellongated ellipsoidal shape with round ends was over 95% in C. acutatum isolated from pepper. However, C. acutatum isolated from boxthorn produced ellongated ellipsoidal conidia with the rate of 75%, and the others were pointed at one or both ends. Regardless of species of Colletotrichum, all isolated used in this study was showed an optimal temperature at $25^{\circ}C$. $EC_{50}$ values of all isolates of Colletotrichum spp. to 2 fungicides as carbendazim and the mixture of carbendazim and diethofencarb was investigated by an agar dilution method. With C. acutatum isolates from pepper belonged to A2 group, the mean of $EC_{50}$ value to carbendazim and the mixture of carbendazim and diethofencarb was 0.68 and $3.16{\mu}g/ml$, respectively. In the case of C. acutatum isolates from boxthorn, which were divided into 2 groups as A1 and A3 group, that to carbendazim was 0.21 at A1 and $0.24{\mu}g/ml$ at A3, while that to the mixture was 1.52 and $3.35{\mu}g/ml$. Isolates of C. gloeosporioides showed the mean of $EC_{50}$ value was $0.12{\mu}g/ml$ to carbendazim and $0.92{\mu}g/ml$ to the mixture. The value of resistant factor was higher in the isolates of C. acutatum obtained in boxthorn than those from pepper.
병든 고추와 구기자 열매에서 분리한 탄저병균 11균주와 36균주를 동정한 후, 몇 가지의 균학적 특징과 살균제에 대한 반응을 조사하였다. 고추에서 분리한 병원균은 모두 Colletotrichum acutatum의 A2 그룹으로 동정되었다. 구기자에서 분리한 병원균은 14균주가 C. gloeosporioides, 22균주가 C. acutatum으로 동정되었으며, C. acutatum 균주는 15균주가 A1 그룹, 7균주가 A3 그룹에 속하였다. $25^{\circ}C$의 PDA 배지에서 10일간 배양한 후 병원균 균총의 색깔을 조사한 결과, 분리한 기주에 관계없이 C. acutatum은 회백색의 균총을 보였으며, C. gloeosporioides는 균총의 중앙은 주황색을, 주변부로 갈수록 회백색과 주황색이 혼재된 색깔을 나타냈다. 고추에서 분리한 C. acutatum의 분생포자 중에서 양끝이 둥근 형태을 나타내는 포자의 비율은 95% 이상이었으나, 구기자 균주는 75%로, 약 25%의 분생포자가 최소한 한 쪽이 뾰족한 형태를 나타내었다. 실험에서 사용한 모든 균주는 Colletotrichum의 종에 관계없이 $25^{\circ}C$가 생장 적온이었다. 한천희석법을 통해서 조사한 고추의 C. acutatum A2 그룹에 속하는 균주의 carbendazim과 carbendazim/diethofencarb 대한 평균 $EC_{50}$값은 0.68과 $3.16{\mu}g/ml$이었으며, 구기자의 C. acutatum A1과 A3 그룹은 carbendazim에 대해서 0.21과 $0.24{\mu}g/ml$, 그리고 합제에 대해서는 1.52와 $3.35{\mu}g/ml$이었다. 또한 구기자에서 분리 한 C. gloeosporioides의 평균 $EC_{50}$값은 각각의 살균제에 대해서 0.12와 $0.92{\mu}g/ml$이었다. 두 살균제에 대한 저항성 요인 값(Rf값)은 구기자에서 분리한 C. acutatum 균주 집단이 고추 균주 집단보다 더 높았다.
