In vitro selection of fungicides for control of leaf blight of sweet persimmon tree caused by Pestalotiopsis theae

In vitro에서 단감나무 둥근갈색무늬병 방제를 위한 살균제 선발

In vitro experiments, several fungicides including prochloraz, tebuconazole, fluazinam, fludioxonil, and iminoctadine-triacetate showed more than 85% inhibition of mycelial growth of Pestalotiopsis theae (SP-3). Dichlofluanid and chlorothalonil inhibited mycelial growth at the rate of 10 and 33%, however benomyl did not inhibit mycelial growth of the fungus. Minimum inhibitory concentration(MICs) of iminictadine-triacetate on the mycelial growth of SP-3 isolate was $10{\mu}g/m{\ell}$, but that of P. theae $\underline{MAFF}$ 752002 and P. longiseta $\underline{MAFF}$ 752001 was $1{\mu}g/m{\ell}$. MIC of benomyl, chlorothalonil, dichlorofluanid was $1,000{\mu}g/m{\ell}$, and that of fludioxonil, fluazinam, tebuconazole was $10{\mu}g/m{\ell}$. Conidial germination was inhibited more than 80% in tile medium which contained $1{\mu}g/m{\ell}$ of prochloraz, tebuconazole, fluazinam, fludioxonil, and minoctadine-triacetate. Control values of benomyl, chlorothalonil and dichlofluanid were 40, 60 and 30%, respectively. The controlling effect of iminoctadine-triacetate ($10{\mu}g/m{\ell}$) aganist P. theae (SP-3) in leaf disc test was more than 93%, but benomyl and dichlofluanid could not control leaf blight disease caused by P. theae (SP-3). Tebuconazole, fluazinam, fludioxonil, and iminoctadine-triacetate showed more than 94% of protective and curative effect of leaf blight of sweet persimmon, while, benomyl and dichlofluanid did not show any control effect of the disease.

국내에 등록된 살균제를 대상으로 Pestalotiopsis theae (SP-3)에 의해 발생되는 단감나무 둥근갈색무늬병 방제약제 선발을 위하여 in vitro에서 병원균의 생장에 미치는 영향을 조사하였다. 대상 약제 중 prochloraz, tebuconazole, fluazinam, fludioxonil, iminoctadine-triacetate 등은 $10{\mu}g/m{\ell}$에서 85% 이상, dichlofluanid과 chlorothalonil은 각각 10%, 33%의 균사생장 억제율을 나타내었으나, benomyl은 전혀 억제시키지 못하였다. 이들의 균사생장 최소억제농도 (MIC)는 iminictadine-triacetate가 P. theae SP-3 균수에 대해서는 $10{\mu}g/m{\ell}$인 반면, 대조균인 P. theae $\underline{MAFF}$ 752002와 P. longiseta $\underline{MAFF}$ 752001에 대해서는 $1{\mu}g/m{\ell}$ 미만으로 나타났다. fludioxonil, fluazinam, tebuconazole의 MIC는 $10{\mu}g/m{\ell}$이었고, Benomyl, chlorothalonil 및 dichlorofluanid의 MIC는 $1,000{\mu}g/m{\ell}$ 로 나타났다. 분생포자의 발아는 $1{\mu}g/m{\ell}$의 prochloraz, tebuconazole, fluarinam, fludoxonil, iminoctadine-triacetate가 함유된 배지에서 80% 이상 억제되었고, benomyl, chlorothalonil, dichlofluanid이 함유된 배지에서는 각각 40%, 60%, 30% 억제되었다. 단감나무 잎 절편과 공시균의 포자현탁액을 이용한 약효 검정에서 $10{\mu}g/m{\ell}$ iminoctadine-triacetate는 93% 이상 발병 억제력을 보였으나 동일 농도의 benomyl과 dichlofluanid는 발병을 억제하지 못하였다. 예방 및 치료 효과는 Fludoxonil, tebuconazole, fluazinam 및 iminoctadine-triacetate이 94% 이상을 보인 반면, benomyl과 dichlofluanid은 예방과 치료효과가 나타나지 않았다.