Abstract
The effects of temperature, duration of wetness period, and fungicides on the spore germination, appressorium formation, acervulus formation and lesion development by Colletotrichum spp., cause of soybean anthracnose, and their pathogenicity were assessed in controlled environment. C. gloeosporioides was highly pathogenic on inoculated soybean seeds as high as C. truncatum, whereas remarkably low on the soybean leaves. Spore germination, appressorium formation and mycelial growth of C. gloeosporioides were best at $25^{\circ}C$, but C. truncatum was best at $30^{\circ}C$. It has also done at $15^{\circ}C$, even though it was much retarded. C. truncatum showed high sensitivity to the fungicides, fluazinam and benomyl, meanshile C. gloeosporioides showed to fluazinam and triflumizole. At least 8 hrs. of wetness period was requird for the pathogen to develop lesions at $30^{\circ}C$. When the wetness period was 32 hrs. lesion size of was larger at $25^{\circ}C$ than $30^{\circ}C$, however it was traceable at $20^{\circ}C$. Different sensitivity of Colletotrichum spp. to fungicides suggests that proper fungicide is required to effective control of soybean anthracnose ingected multiply with Colletotrichum spp.
콩 탄저병의 효과적인 관리를 위하여 병원균의 병원성을 비교하고, 포자발아, 부착기 형성, 균사생장 및 병 진전에 미치는 온도와 수분존재시간의 영향, 그리고 살균제에 대한 반응을 조사하였다. C. gloeosporioides의 종자병원성은 C.truncatum과 비슷하게 높았으나 경엽에서의 병원성은 현저히 낮았다. C. gloeosporioides의 포자발아, 부착기 형성, 균사생장 적온은 $25^{\circ}C$였고, C. truncatum의 적온은 $30^{\circ}C$였으며, $15^{\circ}C$에서는 매우 낮았다. 살균제에 대한 반응은 C. truncatum은 fluazinam과 benomyl에 대해, C. gloeosporioides는 fluazinam과 triflumizole에 대해 높은 감수성을 보였다. C. truncatum에 의한 병의 진전율은 수분존재시간이 8시간이면 $30^{\circ}C$에서, 32시간 이상이면 $25^{\circ}C$에서 가장 높았으며, $20^{\circ}C$에서는 매우 낮았다. 살균제에 대한 감수성은 병원균에 따라 차이가 있으므로 Colletotrichum spp. 의 중복감염에 의한 콩 탄저병의 방제를 위해서는 살균제의 정확한 선택이 중요할 것으로 보인다.