- 期刊
- OpenAccess
臺灣楊桃炭疽病菌之鑑定
Identification of Colletotrichum species associated with carambola anthracnose in Taiwan
摘要
由Colletotrichum spp.所引起的楊桃炭疽病是為害楊桃果實最嚴重也最普遍的病害，受害果實完全喪失商品價值。本研究針對2014～2019年採集自臺灣各地的25株楊桃炭疽病菌菌株進行菌種鑑定，部分菌株並作病原性測定依據分生孢子形態及ITS核酸序列，供試菌株均屬C. gloeosporioides species complex。應用多基因（ITS、ACT、TUB2及CHS-1） 序列以及單基因ApMat序列進行親緣關係分析，結果一致顯示楊桃炭疽病菌主要菌種為C. siamense（佔88%），次要菌種為C. fructicola（佔12%）。ApMat基因之分析結果除與多基因者類似外，其解析度甚且更佳。接種試驗證實，兩種病原菌均可對成熟楊桃果實造成感染，且病徵無差異。本文為首篇應用分子生物學技術鑑定臺灣楊桃炭疽病菌的報告。
並列摘要
Carambola anthracnose caused by Colletotrichum spp. affects fruit quality and market values considerably in Taiwan. Twenty-five representative isolates were collected from carambola fruit during 2014~2019 and used for species identification and pathogenicity tests. In addition to conidial morphology, phylogenetic analyses of the isolates were performed based on a 4-gene dataset (ITS, ACT, TUB2, and CHS-1) and ApMat sequences. The two phylogenetic results were similar and consistent and indicated that C. siamense (22 isolates, 88%) was the dominant specie, followed by C. fructicola (3 isolates, 12%) as the minor one. The ApMat-based phylogeny was found to be a superior tool to differentiate Colletotrichum spp., as it provided a finer resolution. We found both C. siamense and C. fructicola could cause anthracnose symptoms on mature carambola fruit after artificial inoculation. The fungus was reisolated from symptomatic fruit, thus fulfilling Koch's postulates. This is the first report of C. siamense and C. fructicola that cause carambola anthracnose in Taiwan.