添加含矽資材對防治芹菜黃葉病之效果評估

Abstract

由 Fusarium oxysporum f.sp. apii (Foa) 所造成的芹菜黃葉病為芹菜栽培上無法連作的主要原因，造成芹菜產業嚴重損失。目前以邁隆粒劑燻蒸或抗病品種的方式並無法有效防治此病害，因此，發展其他替代方案勢在必行。矽有助於許多植物，尤其是單子葉植物，度過生物或非生物逆境。本研究之目的為探討於溫室條件下，不同含矽資材對於防治芹菜黃葉病菌之效果，藉由改善土壤中造成病害之不利因素，達到芹菜土壤的健康管理。結果發現，奈米矽與矽藻素等含矽資材可以抑制Foa孢子發芽，且奈米矽在濃度 200 mg/L時效果最佳。另外，奈米矽針對芹菜黃葉病之生物防治菌 (AB2、AB78 與 PdB5-1) 及芹菜種子均無顯著之負面影響。溫室盆栽試驗中，奈米矽較矽藻素抑制芹菜黃葉病發病情況較佳，而先添加含矽資材 14 天後再接種病原菌者比同時添加含矽資材及接種病原菌者發病情況較為趨緩。而將生物防治菌及 200 mg/L 奈米矽混合使用，較單獨添加生物防治菌或單獨添加 200 mg/L 奈米矽之處理組，發病嚴重程度較低且發病情勢較緩。本研究添加奈米矽對芹菜植體矽含量增加幅度較不顯著，因此，推測芹菜為低含量矽累積者。由以上結果顯示，種植芹菜時應可以使用奈米矽建議濃度為 200 mg/L 作為基肥，來減少芹菜黃葉病所帶來的損失。

Fusarium wilt, caused by Fusarium oxysporum f.sp. apii (Foa), is the major reason for succession cropping obstacle of celery resulting in huge loss of celery production in Taiwan. Current management strategies using soil fumigation and resistant cultivars may not always be available or effective; therefore, development of alternative means are required. Plant species, especially monocots, when subjected to various abiotic and/or biotic stresses, have been found to benefit from application of silicon. Considering the potentials of silicon to protect plant from pathogen attack, the purpose of this study was to determine whether silicon could reduce the disease severity of Fusarium wilt in celery by improving the adverse effects resulted from pathogens in a greenhouse condition. We discovered that silicon application, including nano silicon, diatomite and sericite powder, can effectively reduce the spore germination rate of Foa. At a concentration of 200 mg/L, nano silicon was more effective to reduce spore germination of Foa. In a pot assay, the symptom of Fusarium wilt of celery was dramatically reduced if silicon was applied 14 days before Foa inoculation when compared with plants treated with silicon and Foa at the same time. The antagonistic bacteria AB2 and AB78 and the phenol-degrading bacterium PdB5-1, all of which could alleviate problems of succession cropping obstacles of celery, would not be affected by application of nano silicon. Furthermore, it was also found that the seed germination rate of celery were not significantly different between groups with or without nano silicon treatment. The treatment using biological beneficial bacteria (AB2, AB78 and PdB5-1) and 200 mg/L nano silicon, compared with the treatment only using biological beneficial bacteria and the treatment only using 200 mg/L nano silicon, reduced effectively disease severity and slowed down the disease development. Applying nano silicon would not increase the silicon content of celery significantly; the celery may not require silicon so much. In summary, silicon application, especially nano silicon at 200 mg/L, could be applied as a basal fertilizer in the field while growing celery to protect if for Fusarium wilt disease attack.