- 期刊
台灣地區咖啡果小蠹（Hypothenemus hampei）分離之Isaria javanica CAES1鑑定與致病性測試
Identification and Pathogenicity of Isaria javanica CAES1 Isolated from the Coffee Berry Borer (Hypothenemus hampei) in Taiwan
摘要
本研究自台灣咖啡田間感染真菌死亡的咖啡果小蠹（Hypothenemus hampei）上，分離到蟲生真菌CAES1，該菌株之菌落為白色至淡黃色或灰色，10-30℃均可生長，25℃菌絲生長速率最快。以光學顯微鏡檢視其無性產孢構造，其分生孢子梗分枝末端著生1-4個瓶梗，瓶梗細胞長寬約3.7-5.0-6.4 μm × 1.9-3.0-3.5μm，分生孢子串生，形狀呈橢圓形至長橢圓形，大小約為2.7-3.8-5.4 μm × 1.2-1.6-2.1 μm。以核糖體內轉錄區間（internal transcribed spacer; ITS）、translation elongation factor-1α gene（TEF1）及β-tubulin的核酸序列以最大似然法（maximum likelihood; ML）進行親緣關係樹的重建分析，結果顯示本菌株於3個基因所重建之親緣關係樹均歸類於Isaria javanica的支系。因此，根據型態及分子鑑定，本菌株應屬於I. javanica。以I. javanica CAES1之分生孢子處理咖啡果小蠹，7 d後之累計死亡率為100%，而觀察此菌感染後之產孢過程則發現，此菌於咖啡果小蠹死亡後約2.77 d ± 0.17 d即可於蟲體表面產生分生孢子。本研究為首篇於台灣之咖啡果小蠹上發現I. javanica之報告，且本菌對咖啡果小蠹具致病力，未來具有應用於田間防治咖啡果小蠹之潛力。
並列摘要
An isolate of entomopathogenic fungi, CAES1, was isolated from a naturally infected coffee berry borer (Hypothenemus hampei; CBB) in a coffee field in Taiwan. Colonies of CAES1 were white to pale-yellow or grey. Mycelia could grow in range of 10℃ to 30℃, with the optimal temperature at 25℃, ranging from 10℃ to 30℃. The conidiophores formed branches with phialides in whorls of 1 to 4, with phialides 3.7-5.0-6.4 μm × 1.9-3.0-3.5 μm, and conidia forming in chain, 2.7-3.8-5.4 μm × 1.2-1.6-2.1 μm. CAES1 was identified as Isaria javanica based on morphology and phylogenetic analysis of the sequences of ribosomal internal transcribed spacer (ITS), translation elongation factor-1α (TEF1) and β-tubulin. The cumulative mortality rate of CBB was 100% on the 7th day after treated with conidia of I. javanica CAES1. I. javanica CAES1 sporulated on the surface of CBB 2.77 d ± 0.17 d after CBB died. This is the first record of I. javanica from CBB in Taiwan. It is suggested that I. javanica CAES1 is pathogenetic to the CBB and could be a potential biocontrol agent against CBB in the future.