2024-03-26
【學術亮點】台灣 首例由Erysiphe euonymicola引起的冬青衛矛白粉病報告
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Intelligent Detection: Development of expert diagnosis system for crop cultivation and management【Department of Plant Pathology / Chih-Li Wang / Associate Professor】
智慧檢測：作物栽培管理專家診斷系統開發【植病系王智立副教授】
上架日期：2023/12/5
智慧檢測：作物栽培管理專家診斷系統開發【植病系王智立副教授】
| 論文篇名 | 英文：First report of powdery mildew on Euonymus japonicus caused by Erysiphe euonymicola in Taiwan 中文：台灣 首例由Erysiphe euonymicola引起的冬青衛矛白粉病報告 |
| 期刊名稱 | Plant Disease |
| 發表年份, 卷數, 起迄頁數 | 2023 |
| 作者 | Huang-Hsi Chu; Xin-Jie Chen; Chih-Li Wang (王智立)* |
| DOI | 10.1094/PDIS-06-23-1055-PDN |
| 中文摘要 | 冬青衛矛（Euonymus japonicas Thunb.）為台灣常見之觀賞用綠籬植物。2020年3月，冬青衛矛於台灣台中市發生嚴重白粉病，大約 90% 的植物在嫩芽的葉子和花梗上表現出白粉病症狀。隨後幾年的3月至6月，台中市和台北市的其他地區也出現了類似的症狀。感染的最初跡象表現為葉子上出現圓形褪綠斑點，隨後斑點的上表面或下表面被白色菌絲體覆蓋。病原菌之形態特徵與Eysiphe euonymicola U. Braun (Braun and Cook 2012) 相符，是在衛矛屬植物上所通報的白粉菌屬病原菌之一。對一公尺高的冬青衛矛進行致病性測定，將受感染的葉子輕輕塗抹在四株健康植物的所有葉子上。使用四株未接種的植物作為對照。將所有 8 株受檢植物封裝在塑膠袋中，在 28 ± 2°C 的條件下保持高濕度 3 天。接種後 7 天 (dpi)，不到 1 個月大的葉子上開始出現褪綠斑點。到 28 dpi 時，所有接種的植物均表現出症狀。三個月以下的葉子上斑點擴展或合併並形成緻密的菌絲體層，而成熟的深綠色葉子則無症狀。在對照植物的任何葉子上均未觀察到任何症狀。接種植株病原菌形態特徵及ITS、LSU序列與上述資訊相符。基於這些發現，E.euonymicola被鑑定為冬青衛矛白粉病的病原體，這是台灣首次有記錄通報此病害。憑證樣本TNM F0037001（分離株EPM-1）保存於台灣國立自然科學博物館。此病菌近年來屢有報道，嚴重影響冬青衛矛的觀賞價值。 |
| 英文摘要 | The Japanese spindle (Euonymus japonicus Thunb.) is commonly used as an ornamental hedge plant in Taiwan. In March 2020, a severe powdery mildew disease was observed on E. japonicus surrounding a city park spanning six hectares in Taichung city, Taiwan. Around 90% of the plants showed symptoms on the leaves and pedicels of young shoots. Similar symptoms were observed in other districts of Taichung city and Taipei city between March to June in subsequent years. Initial signs of infection manifest as circular chlorotic spots on the leaves, which are subsequently covered by white mycelia on either the upper or lower surfaces of the spots. In severe cases, both sides of the leaves become entirely covered by dense mycelia. Hyphal appressoria were solitary or in opposite paired, lobed to multilobed. Conidiophores grow erectly from the hyphae, consist of 2-3 cylindrical cells, 38.9 to 78.6 × 6.31 to 8.28 µm (n = 30). Foot cells are usually straight or slightly flexuous, 23.6 to 43.2 µm (n = 30), followed by 1 to 2 shorter cells. Ellipsoidal conidia are produced singly on the conidiophores, 24.1 to 36.3 × 10.6 to 14.97 µm (n = 30), without fibrosin bodies. Germ tubes are mostly subterminal, sometimes terminal, occasionally exhibiting a longitudinal pattern. Chasmothecia were not observed. These morphological characteristics correspond to the description of Erysiphe euonymicola U. Braun (Braun and Cook 2012), one of the Erysiphe species reported on E. japonicus. Genomic DNA was extracted from seven isolates obtained from different plants in the affected regions. The internal transcribed spacer (ITS) and 28S large subunit (LSU) of rDNA sequences (ITS accession nos.: OR073423-OR073429; LSU accession nos.: OR073448-OR073454) were amplified and sequenced using primer sets PMITS-1 / PMITS-2 (Cunnington et al. 2003) and NLP2 / PRM2 (Bradshaw and Tobin 2020), respectively. The resulting sequences exhibited identities ranging from 99.1 to 100% in ITS and 100% in LSU when compared to the corresponding sequences of E. euonymicola MUMH 133 (ITS: AB250228; LSU: AB250230) (Limkaisang et al. 2006). Phylogenetic analysis based on the concatenated sequences of ITS and LSU clustered the seven isolates within the same clade as three E. euonymicola isolates (MUMH 133, MUMH 6999 and MUMH 7012). Pathogenicity assays were conducted on one-meter tall E. japonicus plants by gently smearing infected leaves on all leaves of four healthy plants. Four uninoculated plants were used as control. All eight assayed plants were enclosed in plastic bags to maintain high humidity at 28 ± 2°C for 3 days. Chlorotic spots began to appear on leaves younger than one month old at 7 days post inoculation (dpi). By 28 dpi, all inoculated plants showed symptoms. Spots expanded or merged and formed a dense mycelial layer on leaves younger than three months, while mature dark green leaves were asymptomatic. No symptoms were observed on any leaves of the control plants. The morphological characteristics and sequences of ITS and LSU of the pathogen from the inoculated plants matched the above information. Based on these findings, E. euonymicola was identified as the causal agent of powdery mildew on E. japonicus, representing the first documented report of this disease in Taiwan. A voucher specimen TNM F0037001 (isolate EPM-1) was deposited in the National Museum of Natural Science, Taiwan. The pathogen has been frequently reported in recent years and significantly impacts the ornamental value of Euonymus spp. (Abbasi and Braun 2020; Lee et al. 2015; Li et al. 2011; Pei et al. 2022). This report also provides an evidence of an ongoing outbreak of the pathogen. |
| 發表成果與AI計畫研究主題相關性 | Erysiphe euonymicola為引起植物白粉病之病原體，該文章為台灣首篇記錄該病害發生之研究內容。病害研究可協助了解植物病原菌之生物特性與造成作物病害之關係，進而實施相關防治措施以降低植物病害造成之影響。該研究與其應用可於智慧檢測上，與作物專家診斷系統之知識庫內容進行結合，以進行病害診斷，並作為制訂病害防制策略之參考。 |
