Qu Tianli, Grey Timothy L, Csinos Alexander S, Ji Pingsheng
Chemistry and Pharmacy College, Qingdao Agricultural University, Shandong 266109, China; and Department of Plant Pathology, University of Georgia, Tifton 31794.
Department of Crop and Soil Sciences, University of Georgia.
Plant Dis. 2016 Sep;100(9):1931-1936. doi: 10.1094/PDIS-03-16-0370-RE. Epub 2016 Jun 30.
Production of bell pepper is seriously affected by Phytophthora capsici, the causal agent of Phytophthora blight. Limited approaches are available for effective management of the disease. Oxathiapiprolin is a fungicide recently registered in the United States that suppressed P. capsici and reduced Phytophthora blight on bell pepper significantly in our previous studies. It is unknown whether oxathiapiprolin translocates in bell pepper plants systemically after application. Experiments were conducted to determine uptake of oxathiapiprolin by bell pepper plants and its systemic movement in the plant. Quantification of oxathiapiprolin in plant tissues was conducted by high-performance liquid chromatography (HPLC) that detected the compound sensitively and selectively. Percentage of recovery of oxathiapiprolin from plant tissues was calculated by comparing the quantities in plant tissues determined by HPLC with known quantities of the compound added to the plant tissues. Recovery rates of oxathiapiprolin from pepper plant tissues ranged from 87.0 to 119.3%. When oxathiapiprolin was applied to roots of bell pepper plants grown in hydroculture, the compound was detected in the root within 4 h and in the cotyledon, first true leaf, and second true leaf within 8 h. It was detectable in the top new leaf 48 h after application to the root. In greenhouse studies with bell pepper plants grown in pots, oxathiapiprolin was applied as a soil drench at 100 and 400 μg/ml. The compound was detected in the root within 3 days and in the stem and first true leaf within 6 days when applied at 100 μg/ml. It was detected in the root, stem, first true leaf, and top new leaf within 3 days when applied at 400 μg/ml. Phytophthora blight on pepper foliage was significantly reduced when oxathiapiprolin was applied as a soil drench at 100 or 400 μg/ml under greenhouse conditions. This is the first report indicating systemic movement of oxathiapiprolin in pepper plants that provides useful information for designing fungicide application programs for effective management of the disease.
辣椒疫霉病严重影响甜椒的生产，辣椒疫霉是引起疫病的病原体。目前有效的病害防治方法有限。恶唑菌酮是一种最近在美国注册的杀菌剂，在我们之前的研究中，它能抑制辣椒疫霉，显著减轻甜椒的疫病。尚不清楚恶唑菌酮施用于甜椒植株后是否能在植株内进行系统运输。为此开展了实验，以确定甜椒植株对恶唑菌酮的吸收及其在植株内的系统移动情况。通过高效液相色谱法（HPLC）对植物组织中的恶唑菌酮进行定量分析，该方法能灵敏且选择性地检测该化合物。通过比较HPLC测定的植物组织中的恶唑菌酮含量与添加到植物组织中的已知量化合物，计算恶唑菌酮从植物组织中的回收率。恶唑菌酮从辣椒植株组织中的回收率在87.0%至119.3%之间。当将恶唑菌酮施用于水培甜椒植株的根部时，4小时内在根部检测到该化合物，8小时内在子叶、第一片真叶和第二片真叶中检测到。在根部施用后48小时，在顶部新叶中可检测到该化合物。在温室盆栽甜椒植株的研究中，以100和400μg/ml的浓度进行土壤浇灌施用恶唑菌酮。当以100μg/ml施用时，3天内在根部检测到该化合物，6天内在茎和第一片真叶中检测到。当以400μg/ml施用时，3天内在根部、茎、第一片真叶和顶部新叶中检测到。在温室条件下，当以100或400μg/ml的浓度进行土壤浇灌施用恶唑菌酮时，辣椒叶片上的疫病显著减轻。这是第一份表明恶唑菌酮在辣椒植株内进行系统移动的报告，为设计有效的病害防治杀菌剂施用方案提供了有用信息。
