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Title: | 評估土壤根際潛力菌株搭配菊科植物添加物之生物防治功效 Evaluation of the biocontrol effects exerted by an elite rhizobacterial strain formulated with Asteraceae plant additive |
Authors: | 劉彥妤 Yen-Yu Liu |
Advisor: | 劉啟德 Chi-Te Liu |
Keyword: | 細菌性果斑病,果斑病原菌,土壤根際潛力菌株,菊科植物添加物,生物防治, bacterial fruit blotch (BFB),Acidovorax avenae subsp. citrulli,rhizobacterium,Asteraceae plant,biocontrol, |
Publication Year : | 2018 |
Degree: | 碩士 |
Abstract: | 瓜類細菌性果斑病 (bacterial fruit blotch) 由細菌性果斑病菌(Acidovorax avenae subsp. citrulli, Aac) 所引起。種子為其初級感染源,高溫、下雨等因素會造成病原菌快速蔓延,導致嚴重的經濟損失。傳統法會將種子浸泡在低濃度鹽酸或是次氯酸鈉等化學藥劑藉以抑制果斑病原菌,但衍生出對環境非友善或是食品安全疑慮等問題。本研究的目的為評估一株具有防治植物病害的潛力菌株搭配菊科植物添加物後對於瓜類細菌性果斑病的防治效果。根據對峙培養的實驗結果,潛力菌株與菊科植物添加物之處理組可成功抑制果斑病原菌的生長,然而除去菌體的上清液則無抑制效果,顯示其拮抗效果來自於活菌。我們進一步探討菊科植物添加物對於潛力菌株的微生物生理影響,結果顯示菊科植物添加物不僅可促進潛力菌株的生物膜生成能力,也提高菌體活性。在盆栽試驗發現,預先接種潛力菌株或是接種潛力菌株搭配菊科植物添加物的美濃瓜種子其病徵較為輕微,而且植株內的Aac 的數量都較未接種組低。全基因解序結果顯示該潛力菌株基因體大小約為4.00 Mb,經過序列比對與功能註解分析,潛力菌株含有約3,900 條蛋白質編碼基因(protein-coding gene),包括數種抗生物質相關基因。此外,基因體中亦含有與生物膜形成相關的同源基因,這些基因與促進植物生長和生物防治有著密切關係。綜合上述結果,潛力菌株與菊科植物添加物的配方具有成為防治細菌性果斑病潛力的綜效型生物製劑。 Bacterial fruit blotch (BFB) of curcubits is caused by Acidovorax avenae subsp. citrulli (Aac) which is a seed-borne pathogen and cause serious threat in cucurbit industry worldwide. Although seed treatments with hydrochloric acid or sodium hypochlorite can suppress Aac infection, they generally fail to eradicate the bacterium. The aim of this study was to evaluate the synergistic effects of an elite rhizobacterial strain and Asteraceae plant additive on inhibition of BFB. Under in vitro antagonistic test, both rhizobacterial strain and the combination of rhizobacterial strain with Asteraceae plant additive could inhibit Aac. We noted that the supernatant of rhizobacterial strain did not inhibit Aac, suggesting the biocontrol effectiveness derived from the living cells. We further investigated the effects of Asteraceae plant additive on physiological activities of rhizobacterial strain. We found the plant additive enhanced not only its biofilm formation, but also the cell vitality. In pot experiments, while pre-treating the melon seeds with either single-strain (rhizobacterial strain) inoculant or with the mixed treatment (rhizobacterial strain + plant additive) showed higher inhibitory effects against BFB than that without inoculation. The complete genome of rhizobacterial strain was analyzed by next generation sequencing. The results of whole genome sequencing indicated that rhizobacterial strain has one circular chromosome that is around 4.00Mb with 3,900 protein-coding genes, including several antibiotic-related genes. In addition, we also identified the homologous genes related to biofilm formation that is associated with the beneficial traits of growth promotion and biocontrol activities. Taken together, the rhizobacterial strain formulated with Asteraceae plant additive can act as a potential biocontrol agent against BFB. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/7373 |
DOI: | 10.6342/NTU201804077 |
Fulltext Rights: | 同意授權(全球公開) |
metadata.dc.date.embargo-lift: | 2024-02-19 |
Appears in Collections: | 生物科技研究所 |
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ntu-107-1.pdf | 2.23 MB | Adobe PDF | View/Open |
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