草莓灰黴病菌對殺菌劑百克敏、貝芬替、白克列及邁克尼抗藥性之分子檢測

Molecular detection of insensitivities to the fungicides pyraclostrobin, carbendazim, boscalid and myclobutanil in Botrytis cinerea in Taiwan

Botrytis cinerea引起的灰黴病是台灣許多作物的重要病害，為防治灰黴病需頻繁且大量施用化學藥劑，常造成嚴重的抗藥性問題。為評估灰黴病菌抗藥性分子檢測的可行性，乃以2018~2019年採自全台各草莓產區的36株灰黴病菌單胞菌株，用菌絲半抑制有效濃度（effect concentration for 50% inhibition, EC50）評估其對百克敏、貝芬替、白克列及邁克尼等4種不同作用機制殺菌劑的感受性，並以聚合酶連鎖反應及基因定序技術分析各菌株對上述4種藥劑抗藥相關基因特定密碼子的變異。結果顯示，抗百克敏、貝芬替、白克列及邁克尼菌株分別具以下4類基因點突變：G143A（cytb）、E198A/V（β-tubulin）、N230I及H272R/Y（sdhB）及Y136F（CYP51），且例外極少，證實灰黴病菌抗藥性分子檢測具可行性。此外，供試36株菌中抗百克敏、貝芬替、白克列及邁克尼者分別有31、32、25及1株；同時抗百克敏及貝芬替者有31株，同時抗百克敏、貝芬替及白克列者有25株，這警示灰黴病菌多重抗藥性問題很嚴重。

Botrytis cinerea is one of the most devastating fungal pathogens on many crops in Taiwan. Thirty-six single-conidium isolates collected from strawberry fields during 2018~2019 were investigated for fungicide sensitivity in this study. We evaluated the effective concentrations for 50% mycelial growth inhibition (EC50) of four fungicides for each isolate and determined possible association with target site mutations in the cytb,β-tubulin, sdhB and CYP51 genes responsible for insensitivity to the fungicides pyraclostrobin (quinone outside inhibitor), carbendazim (benzimidazole), boscalid (succinate dehydrogenase inhibitor) and myclobutanil (sterol demethylation inhibitor), respectively. The results indicated that fungal insensitivities to the respective fungicides were highly associated with previously published genotypes, including G143A in cytb; E198A/V inβ-tubulin; N230I and H272R/Y in sdhB; and Y136F in CYP51. Accordingly, molecular detection of fungicide insensitivity of B. cinerea is practicable. Furthermore, the numbers of isolates with insensitivity to pyraclostrobin, carbendazim, boscalid and myclobutanil were 31, 32, 25 and 1, respectively. The numbers of isolates with multifungicide insensitivities of two (pyraclostrobin and carbendazim) and three (plus boscalid) were 31 and 25, respectively.