應用Bacillus amyloliquefaciens防治由Xanthomonas campestris pv. campestris所引起之甘藍細菌性黑腐病

Application of Bacillus amyloliquefaciens to control black rot disease on cabbage caused by Xanthomonas campestris pv. campestris

甘藍細菌性黑腐病是由Xanthomonas campestris pv. campestris（Xcc）所引起，且被認為在全世界是十字花科中最重要的病害之一。目前許多研究已證明可利用拮抗微生物來防治此病害的發生。本研究之目的為利用土壤分離之Bacillus amyloliquefaciens PMB04及PMB05菌株來評估其是否具有防治甘藍黑腐病能力。首先在平板拮抗活性分析中，PMB04及PMB05菌株皆對於Xcc不同菌株均有抑制的效果。進一步將預先接種有Xcc之種子分別處理上述兩種拮抗菌菌株來評估其對甘藍黑腐病之防治效果。結果顯示，此兩種拮抗菌株對甘藍黑腐病的罹病率與罹病度均有顯著的抑制效果，其中又以PMB05菌株的處理為佳。然而在種子處理後，PMB04菌株相較於PMB05菌株可大幅降低幼苗中病原菌族群。為了進一步了解此些拮抗菌株在誘導抗病上的活化，利用癒傷葡聚醣的觀察進行分析。結果顯示僅PMB05菌株能夠在同時接種有Xcc的情況下加強此植物防禦反應之訊號，推測PMB05菌株對黑腐病之抑制效果可能與其在植物防禦訊號的提升有關。綜上所述，本研究說明在防治甘藍黑腐病上可利用具有拮抗效果或提升植物防禦反應的B. amyloliquefaciens菌株為可行的策略。

"Black rot disease (BRD) caused by Xanthomonas campestris pv. campestris (Xcc) is considered the most important disease of crucifers worldwide. Various strategies have been developed to control BRD on cabbage, including the use of antagonistic microorganisms. In this study, we tested the efficacy of antagonistic Bacillus amyloliquefaciens strains, PMB04 and PMB05, in controlling BRD of cabbage. We found these two antagonistic strains inhibited Xcc growth in dual culture assays and suppressed BRD by seed treatment. To gain more insights on the differential antagonism employing by PMB04 and PMB05, the callose deposition was assayed as an indication of the activation of plant defense response. The cabbage leaves treated with PMB05 showed increased callose deposition upon the inoculation of Xcc in comparison with the ones treated with PMB04 and water, suggesting the application of B. amyloliquefaciens PMB05 strongly suppressed the disease severity of BRD by activating plant basal defense and inhibiting Xcc growth, whereas B. amyloliquefaciens PMB04 greatly reduced the growth of Xcc in the seedlings. The results of this research indicate the development of B. amyloliquefaciens strains as biocontrol agents has a great potential to control BRD of cabbage in the future."