- 期刊
臺灣番椒上之番椒疫病菌（Phytophthora capsici）對滅達樂之抗感性分析
Evaluation on Metalaxyl Sensitivity of Phytophthora capsici Isolates Collected from Pepper in Taiwan
摘要
番椒疫病菌（Phytophthora capsici Leon）為臺灣番椒生產的主要限制因子之一，施用化學藥劑是此病害的主要防治方法。於國外滅達樂（metalaxyl）與右滅達樂（mefenoxan）常推薦用於防治此病害，且已有抗藥性菌株出現的相關報告。雖滅達樂在臺灣未正式推薦用於防治此病害，然各農業改良場針對番椒疫病或其他由卵菌類所引起之病害時，滅達樂亦為推薦防治藥劑之一，因此田間常看見農民施用滅達樂防治番椒疫病或卵菌類病害，然臺灣尚無番椒疫病菌對滅達樂抗感性的相關報告。本研究目的為檢測引起臺灣番椒疫病之P. capsici對滅達樂的感受性。並且比較三種病原型（Pathotype 1, 2和3）和不同配對型（A1和A2 mating type）菌株對滅達樂之感受性。亞蔬－世界蔬菜中心自1987－2008年間蒐集引起臺灣番椒疫病之P. capsici菌株共171株。自1987－2007年間蒐集的118株皆為A1配對型，2008年蒐集的53株菌株中有15株為A2配對型。測試這171株菌株對滅達樂藥劑的感受性，結果得知所測試的臺灣番椒疫病菌株對滅達樂藥劑仍屬敏感64.9 %（111/171），而中度敏感與抗藥性比率分別為19.3%（33/171）與15.8%（27/171）。比較1987－2006年、2007和2008年的菌株對滅達樂藥劑的抗感性，結果顯示菌株對滅達樂的抗性由 0%（0/104）增加至28.6%（4/14）和43.4%（23/53）。評估番椒疫病菌三種病原型對滅達樂之感受性，得知57.1%（8/14）病原型1菌株對滅達樂表現抗性，而病原型2與3菌株則分別為 6.1%（3/49）和14.8%（16/108）。分析2008年番椒疫病菌A1與A2配對型菌株對滅達樂的感受性，得知在各病原型內之A1配對型菌株抗滅達樂之比率介於51.7~100.0%；而A2配對型菌株抗滅達樂之比率則介於0.0~66.7%。此結果指出2008年所蒐集的新菌株中，A1配對型菌株對滅達樂的抗藥性較A2配對型強。由上述結果顯示，引起臺灣番椒疫病之菌株對滅達樂的抗性有增加的傾向，此外田間已出現A2配對型菌株，未來將可能導致更多抗性或低感受性P. capsici 菌株增加。
並列摘要
Phytophthora blight of pepper caused by Phytophthora capsici Leon is one of the major limiting factors of pepper production in Taiwan. Application of fungicides was the mainly control strategy. Metalaxyl and related products have been reported as one of fungicides for conrolling pepper blight caused by P. capsici. However, the metalaxyl-resistant isolates of P. capsici have been detected out of Taiwan. Although the metalaxyl is not recommended to use for controlling pepper blight in Taiwan, the District Agricultural Reasearch and Extension Station of Taiwan often recommend the metalaxyl for controlling Phytophthora blight on pepper. Thus, the informations of sensitivity of P. capsici to metalaxyl are important for managing pepper blight. The objective is to examin the sensitivity of P. capsici to metalaxyl in Taiwan. Moreover, the sensitivities of different pathotype or mating type isolates to metalaxyl were also compared. AVRDC–The world vegetable center collected 171 isolates of P. capsici from important pepper production areas in Taiwan since 1987 to 2008. There were A1 mating type of 118 isolates collected in 1987-2007, 15 of 53 isolates were A2 mating type collected in 2008. Based on in vitro assessment of metalaxyl sensitivity of P. capsici isolates, 64.9 % (111/171) of the isolates were classified as sensitive, 19.3 % (33/171) as intermediate, and 15.8 % (27/171) were resistant to metalaxyl. The isolates collected in 1987-2006, 2007and 2008 were compared and the results showed that the resistance to metalaxyl was increased from 0% (0/104), 28.6% (4/14) to 43.4% (23/53), respectivitly. In addition, 57.1% (8/14) isolates of pathotype 1 were resistant to metalaxyl, and the resistant isolates of pathotype 2 and 3 were 6.1% (3/49) and 14.8% (16/108), respectively. Result was pathotype 1 more resistance on metalaxyl. Futhermore, the sensitivity of different mating type collected in 2008 to matalaxyl showed that the resistant ratios of A1 mating type isolates to metalaxyl were 51.7-100.0% and A2 isolates to metalaxy were 0.0-66.7%. Verification A2 mating type isolates were more sensitive to metalaxyl than A1 isolates. The number of P. capsici resistance to metalaxyl was substantially increased and appearance of A2mating type may lead to difficulties of disease control in the future.