台灣本土白殭菌於咖啡果小蠹之田間自然感染率及菌株篩選

白殭菌 (Beauveria bassiana) 為目前國外防治咖啡果小蠹 (Hypothenemus hampei) 重要微生物資材，由於我國現行尚無白殭菌商品可供咖啡產業應用，故本研究目的一方面調查此菌於本土咖啡園自然感染率，另一方面收集本土白殭菌菌株，透過分離、鑑定及室內生物檢定，篩選出具防治咖啡果小蠹潛力菌株供製劑開發。研究結果顯示，白殭菌於不同咖啡園自然發生率差異頗大，於雲林縣古坑鄉試區 (粗放栽培)，蟲蛀果內咖啡果小蠹雌蟲感染白殭菌比例最高達13.3% (平均3.1%)，以3–6 月為白殭菌盛行期，該期間平均70.0% 雌蟲死亡個體皆感染白殭菌。於南投縣仁愛鄉試區 (慣行栽培)，白殭菌感染率極低，最高僅4.9% (平均0.6%)。潛力菌株篩選上，已自台中市、南投縣及雲林縣等不同產區採集98 株分離株，並挑選7 株菌株作為候選菌株，經室內培養形態與ITS、Bloc 及EF1 序列分析鑑定後，確認皆屬B. bassiana。各菌株於不同環境溫度下菌絲生長、孢子發芽及對咖啡果小蠹致死能力均存在差異，以分離株B005、B025 及B068 較具耐高溫特性，於32℃下孢子發芽率分別達98%、94% 及88%，其他菌株發芽率則介於30–60%。多數菌株於25℃下致死能力較佳，接種後第7 日前即可達100% 致死率。於32℃高溫環境下各菌株致死能力明顯下降，於接種後第8 日前皆無法達100% 致死率，但仍以分離株B005、B039 及B068 表現較佳，第8 日致死率分別為67%、72%及77%。後續研究將持續菌株篩選，並先行以分離株B068 等耐高溫菌株進行製劑，希冀未來能開發適合台灣防治咖啡果小蠹的本土白殭菌產品，裨益我國咖啡產業發展。 Beauveria bassiana (Bb) is an important microbial biocontrol agent for controlling the coffee berry borer (CBB, Hypothenemus hampei) in many countries; however, no commercial Bb product is currently available to the coffee industry in Taiwan. Therefore, the aims of this study were to investigate the natural infection rate of CBB in local coffee orchards, and to screen native Bb isolates as potential control agents against CBB through isolation, identification, and laboratory tests. The results showed that the natural prevalence of Bb varied dramatically among different orchards. In an experimental orchard in Gukeng Township, Yunlin County (extensive farming), the maximum infection rate of female CBB in infested berries was 13.3% (averaged 3.1%). The incidence peaked from March to June, showing 70.0% of dead CBB females were infected with Bb. However, in the other orchard in Ren-ai Township, Nantou County (conventional farming), the infection rate was very low, with a maximum of only 4.9% (averaged 0.6%). To screen isolates with biocontrol potential, a total of 98 isolates were collected from the production areas, including Taichung, Nantou, Yunlin, etc. Seven isolates were selected and identified as Bb by cultural morphology and DNA sequences of internal transcribed spacer, B locus intergenic region, and translation elongation factor 1-α. The mycelial growth rate, spore germination rate, and virulence to CBB varied among isolates at different temperatures. Isolates B005, B025, and B068 were more tolerant to high temperatures, the spore germination rates of which were 98%, 94%, and 88% at 32℃, respectively, while the germination rates of most other isolates were 30–60%. Most isolates had higher virulence to female CBB at 25℃ , resulting in a mortality rate of 100% 8 days post-inoculation (dpi). All isolates failed to cause 100% mortality 8 dpi at 32℃, while B005, B039, and B068 had better performance, which caused 67%, 72%, and 77% mortality 8 dpi, respectively. In future research, we will continue screening isolates with biocontrol potential, and formulate Bb products with B068. We hope to develop commercial Bb products that will be suitable for managing CBB in the Taiwanese coffee cultivation system and help to improve the coffee industry.

Subjects

咖啡果小蠹

白殭菌

生物防治

coffee berry borer

Beauveria bassiana

biological control

Publisher

農業試驗所

Type

journal article

File(s)

Name

72-3-3.pdf

Size

2.86 MB

Format

Adobe PDF

Checksum

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