己酸誘導抗性對番茄抗病害之防治研究

番茄為茄科 (Solanaceae)茄屬 (Solanum) 之草本植物，是重要的世界性果菜兩用作物，因此其大部分病蟲害防治技術都相當成熟，但目前仍有部分病害難以利用現有的技術防治，而只能利用綜合病蟲害管理 (Integrated Pest Management, IPM) 來達到管控病蟲害的目的。利用己酸作為誘導物使植物產生誘導抗性是一種對環境友善的方式，而且便於與各種防治技術結合。本研究以對峙培養測試了己酸對青枯病菌 (Ralstonia solanacearum)和腐黴菌 (Pythium aphanidermatum) 於培養基上的抑菌效果，並確認其抑菌效果是來自於己酸的酸性，並測試番茄幼苗對己酸之可接受濃度達到1000 ppm 而於7天內未有任何不良的影響。另外以盆栽試驗測試預先施用己酸對接種以上兩種病原菌之防治效果，當中在青枯病的防治上較為明顯，而在試驗中也發現己酸對初次接種病原菌的保護效果可長達21天，而且發現提早施用己酸對兩種病害都能更有效的降低其罹病度。在果實上施用己酸浸泡處理能有助減緩腐黴菌和鏈格孢菌在果實上的生長，在植株採樣中也發現己酸處理使接種病害的組別有更高的抗氧化酵素活性，與活性氧 (ROS) 染色之結果互相呼應，證明己酸對番茄的保護效果是基於對植株的誘導抗性。結果表明己酸是一種可誘導番茄對青枯病及幼苗猝倒病產生抗性，且具長效的保護劑，己酸誘導抗性於番茄幼苗上具有作為植物疫苗的潛力，達到降低感病性，減少其他農業藥劑的使用。

關鍵字

番茄 (Tomato) ；己酸 (Hexanoic acid) ；番茄青枯病 (Tomato bacterial wilt) ；番茄幼苗猝倒病 (Tomato damping off) ；誘導抗性 (Induced resistance)

並列摘要

Tomato (Solanum lycopersicum) is a herbaceous plant of Solanaceae family, and an important world-wide crop. Even though most of its pest control technologies have been well developed, some diseases are still difficult to prevent and control. Only the use of Integrated Pest Management (IPM) may help achieve the end-goal of controlling such pests and diseases. Elicitation of plant resistance by hexanoic acid is an environmentally friendly method that can be easily combined with various techniques to effectively control pests. In this study, the antimicrobial effect of Hexanoic acid on Ralstonia solanacearum and Pythium aphanidermatum on the medium was tested and the bacteriostatic effect on Ralstonia solanacearum was determined to be the acidity of the hexanoic acid. The acceptable hexanoic acid concentration of the tomato seedlings was 1000 ppm, which did not have any adverse effects within 7 days. A pot experiment was conducted to test the control effect of pre-administered hexanoic acid on the above two pathogens, among which the control of bacterial wilt was more obvious. It was found that the protection of hexanoic acid on the first inoculation of pathogen can last for 21 days, and that early administration of hexanoic acid can effectively reduce the disease severity of both diseases. Also, application of hexanoic acid on tomato fruits can help slow the growth of Pythium sp. and Alternaria sp. on the fruit. Hexanoic acid treatment induced higher levels of antioxidant enzyme activity to the inoculated disease group, similar to the results of reactive oxygen species (ROS) staining which proves that protection of tomato by hexanoic acid is due to the induced resistance in plants. The results indicate that hexanoic acid is a long-acting protective agent. Hexanoic acid-induced resistance has the potential to be developed into a plant vaccine on tomato seedlings, reducing disease susceptibility and the use of other chemical reagents.