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  • 學位論文

筆筒樹植群生態及其新興病害萎凋病之研究

Studies of the vegetation ecology and an emerging wilting disease of Cyathea lepifera

指導教授 : 沈偉強

摘要


全世界桫欏科蕨類約有500種,廣泛分布於熱帶與亞熱帶地區,相較於其他蕨類更具區域特有性,常作為研究生物地理與演化分布的重要材料。筆筒樹 (Cyathea lepifera (J. Sm. ex Hook.) Copel.) 為桫欏科桫欏屬樹蕨,具明顯直立莖幹,葉片叢生於樹狀莖頂端,於世界分布以臺灣為密度中心,向周圍輻射擴散遞減,分布於中國東南部、菲律賓,以及沖縄。近年,臺灣地區筆筒樹多罹患不明原因萎凋病,罹病初期,少數羽葉呈紅褐色枯萎,隨著病徵發展擴散至整個樹冠,直至葉片全數萎凋脫落,僅剩樹狀莖留存,其中,罹病樹狀莖髓部可觀察到軟腐褐化。筆筒樹萎凋病好發於夏季,病勢進程短,自病徵初期至植株死亡時約一個月。為釐清萎凋病病因,本研究選定臺灣筆筒樹高密度原生地陽明山國家公園作為研究範圍,利用地理資訊系統與正射影像調查筆筒樹族群密度、棲地資訊,以及罹病狀況,配合實地校勘與穿越線調查,選擇具代表性的病株採集地點。陽明山地區估計約有四萬棵筆筒樹,偏好分布在海拔200到600公尺間,中坡率,北向至東向之坡向,以及溪谷地形之棲地。此外,初步的植群調查中並未發現筆筒樹植群結構與罹病有明顯關連。筆筒樹萎凋病發病較嚴重的區域為陽明山東半部的馬槽與萬溪地區,皆為東北坡向,2009年罹病率分別為18.7%與18%;2010年為30.8%與19.1%;2011年則為18.4%與23.3%;設置樣區監測後觀察到病害有持續擴散的現象;是故選擇此兩區域作為罹病樣本主要採集地。完成科霍氏法則後,認為筆筒樹萎凋病主要病因為一新種病原真菌,經鑑定後屬黑腐皮殼菌科,經完成無性與有性世代之誘導後,可產生柄子殼與子囊殼。初步擬定綜合防治策略,為病株袪除、預防性施藥,以及利用專一性引子檢測罹病株。於實驗室中進行藥劑篩選測試,抑制效果良好之藥劑種類包括免賴德、亞賜圃、嘉賜黴素、鋅錳乃浦、撲滅寧,以及腐絕;野外施用方法與成效尚待評估。

並列摘要


There were about 500 species in Cyatheaceae around the world, distributed in tropical and subtropical, and usually as important object for researching geobiography and evolution. Cyathea lepifera (J. Sm. ex Hook.) Copel.), also called scalty tree fern, member of Cyatheaceae, usually with erect and unbranched stem, and fronds arranged in a terminal crown. The world distribution of C. lepifera is centered in Taiwan, and radiated out to the surrounding areas, such as southeast part of China, Philippines, and Ryukyu . Recently, many wilted and dead trees of C. lepifera were discovered in Taiwan, called Cyathea lepifera wilt; however, the cause of the death was unknown. For the beginning of symptoms, a few of laminae turned to brownish red and withered, and withering spread with progress, until no frond remained on the terminal of stem. Dissected tree fern to reveal medulla in stem, brown and soft rot tissue was observed. C. lepifera wilt usually occurred in summer and it took about a month from symptoms revealed to dead. For researching etiology of C. lepifera wilt and choosing collection sites of diseased plants, we investigated population, information of habitat of C. lepifera, and epidemiology of wilting with geographic information system and orthophotography in Yangmingshan National Park where were native for C. lepifera. There were more than 40,000 trees estimated of C. lepifera, favor elevation between 200 and 600 meter high, middle slope, north to east aspects, and also prefers to grow in the valley where flow accumulation is greater than zero. Furthermore, in preliminary vegetation surveys showed that no significant variation was observed in the vegetation structure of C. lepifera, suggesting that companion plants may be not involved in the death of tree fern. The area which showed more severe disease incidence included Macao and Wansi, both were in the east part of Yangmingshan, and toward to northeast. Disease rate of Macao and Wansi were 18.7% and 18% for each in 2009; 30.8% and 19.1% for each in 2010; 18.4% and 23.3% for each in 2011. So we decided to collect diseased sample from Macao and Wansi after observed the phenomenon of infection in spreading with setting plots for monitoring. It’s convinced that C. lepifera wilt was caused by a new species in fungus by finishing Koch’s postulates. We thought the fungus belongs to Diaporthaceae after further molecular and morphological identification. So far, we’ve know that fungus reproduce by pycnidia and perithecia. Strategies for integrated pest management, such as pathogen eradication, applying agent for prevention ,and pathogen detection by specifi primers. Effective fungicides including thiabendazole, benomyl, kasugamycin, mancozeb, and procymidone have been identified; however, their application in the field and also disease management strategies need further evaluation.

參考文獻


陳美蓮。1995。臺灣的筆筒樹族群遺傳結構之研究。生物研究所。國立臺灣師範大學。
林育靜。2011。台灣產水玉黴科真菌之分類與親緣關係研究。生命科學院碩士在職專班。中興大學。68頁。
陳文雄。2008。蕨類栽培技術。臺東區農業改良場技術專刊 特10 輯。
Holttum RE, 1963. Cyatheaceae, in: Van Steenis CGGJ, Holttum RE (eds), Flora Malesiana. Martinus NijhoV. Dr. W. Junk, The Hague, Boston, London.
Adams M, Gmunder F, Hamburger M, 2007. Plants traditionally used in age related brain disorders--a survey of ethnobotanical literature. Journal of Ethnopharmacology 113: 363-381.

被引用紀錄


何芫薇(2014)。臺東縣達仁林場筆筒樹健康監測與保育〔碩士論文,國立屏東科技大學〕。華藝線上圖書館。https://doi.org/10.6346%2fNPUST.2014.00221

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