Response of domestically collected Echinochloa species to cyhalofop-butyl and pyribenzoxim herbicides, their absorption and translocation

국내 피 수집종에 대한 cyhalofop-butyl과 pyribenzoxim의 약제반응 및 흡수이행

To investigate the physiological and biochemical differences between susceptible and tolerant species of Echinochloa species to the foliar applied cyhalofop-butyl and pyribenzoxim herbicides, herbicidal response, the rate of absorption, translocation and metabolism were studied. Among 148 individuals of Echinochloa species collected from 41 sampling sites in Korea which were classified into 7 geographical regions, based on morphological characteristics of plant and seed type, 46 lines were used for further studies. From them, E. crus-galli var. praticola collected from Hwanggan and E. crus-galli var. crus-galli collected from Namyangju were selected as the most susceptible species to cyhalofop-butyl and pyribenzoxim, respectively. Meanwhile, E. oryzicola(from Cheju) and E. crus-galli var. crus-galli(from Asan) were selected as tolerant species to cyhalofop-butyl and pyribenzoxim, respectively. Application of radio-labelled herbicides on the 1st leaf to both susceptible and tolerant Echinochloa species exhibited that the applied $^{14}C$-Cyhalofop-butyl and $^{14}C$-pyribenzoxim were more easily absorbed and translocated into stem tissues than root. Absorption of $^{14}C$-Cyhalofop-butyl increased rapidly at 1 h after application and reached the maximum at 12 h after application. However, the absorption rate of $^{14}C$-pyribenzoxim was not changed. Two metabolites from cyhalofop-butyl-treated plants and one metabolite from pyribenzoxim-treated plants were separated by TLC. The amount of metabolite 1 in cyhalofop-butyl-treated tolerant species was significantly higher than that in the susceptible one, suggesting differences in detoxification ability between susceptible and tolerant species.

외부 형태가 다른 피속류 46종을 대상으로 피 방제용 경엽처리 제초제인 cyhalofop-butyl과 pyribenzoxim의 약제반응을 보고, 그 결과 약제반응이 상이한 피속류를 선발하여 $^{14}C$ 화합물을 이용, 흡수이행 및 체내대사 등을 시험하였다. Cyhalofop-butyl에 감수성인 황간 돌피, 내성인 제주 강피 그리고 pyribenzoxim에 감수성인 남양주 물피, 내성인 아산 물피를 선발하였다. $^{14}C$-Cyhalofop-butyl과 $^{14}C$-pyribenzoxim의 피 체내에서의 흡수이행 특성은 내성 피보다는 감수성 피에서 더 빨리 이행되는 경향을 보였으며, 뿌리보다는 지상부의 다른 부위로 이행되는 경향이었다. 감수성 정도가 다른 피속류에 $^{14}C$ 화합물을 처리한 결과, cyhalofop-butyl에서는 2종, pyribenzoxim에서는 1종의 미확인 대사산물이 검출되었으며, 대사산물의 분포비율을 보면 불활성 물질로 추정되는 대사산물의 양은 감수성 피보다 내성 피에서 높았다. $^{14}C$ 화합물을 처리한 피속류에서 결합 잔류물 형태로 잔류한 양은 감수성 피보다 내성 피에서 더 많이 잔류하였다.