液化澱粉芽孢桿菌Nana 11在蝴蝶蘭黃葉病的防治潛力評估

Bacillus amyloliquefaciens Nana 11, a potential biocontrol agent against Phalaenopsis yellowing leaf

蝴蝶蘭植株發生葉片黃化、落葉，在葉鞘或裸露的根部會出現黑腐，有時也會有成堆橙紅色子囊殼產生，此為Fusariumsolani （teleomorph Haematonectria haematococca） 所引起的蝴蝶蘭黃葉病，本研究主要在評估液化澱粉芽孢桿菌 （Bacillusamyloliquefaciens） Nana 11水懸劑在溫室防治蝴蝶蘭黃葉病的可行性。在對峙培養測試中，Nana 11的 200倍稀釋液對黃葉病菌絲生長的干擾抑制率 （the interference and inhibition rate, IIR）為14%，表示Nana 11 200倍水懸劑可以干擾黃葉病菌菌絲的生長。在高接種源濃度 （3.9x105 spores/mL） 的黃葉病菌接種中，接種蝴蝶蘭品種小斑馬 （Phalaenonpsis Taida Little Zebra） 後第23天，相較於水對照處理組100%的發病度，連續澆灌4次Nana11水懸劑400倍稀釋液可使供試植株發病度顯著得降低至84%。在低接種源濃度 （1.3x102 spores/mL） 的黃葉病菌接種中，接種蝴蝶蘭品種綠精靈 （Phal. Green Pixie 'Ever Green'）後第21天，相較於水對照處理組的36%發病度，連續澆灌4次Nana 11水懸劑400倍稀釋液可使供試植株發病度顯著得降低至18%。在採用病害綜合防治管理策略的蝴蝶蘭園中，選用供試蝴蝶蘭A4268 （Doritaenopsis Mount Lip 'Chou'） 2.5吋盆苗株，經每星期、連續7次施用Nana 11水懸劑 400倍稀釋液處理，第77天的發病度為3%，與水對照組處理的16%發病度具有顯著差異。綜合以上結果顯示，B. amyloliquefaciens Nana 11 的400倍水懸劑可用於預防性施藥，每星期施用1次，連續施用4次，可減少蝴蝶蘭黃葉病的發生。

This study was evaluated the feasibility a strain of Bacillus amyloliquefaciens Nana 11 to possess biocontrol activity against Phalaenopsis yellowing leaf caused by Fusarium solani (teleomorph Haematonectria haematococca) in the greenhouse. In the dual culture test, the interference and inhibition rate (IIR) of Nana 11 200-fold dilution was 14% indicating that the Nana 11 dilution could interfere with the mycelial growth of F. solani. In the inoculation with high inoculum density (3.9x105 spores/mL), the control group had a disease severity of 100% on the 23rd day after the inoculation of Phalaenonpsis Taida Little Zebra, and the disease severity of Nana 11 400-fold dilution treatment was 84%. There was a significant difference of 5% between both. In the inoculation with less inoculum density (1.3x102 spores/mL), the control group had a disease severity of 36% on the 21st day after the inoculation of Phal. Green Pixie 'Ever Green', and the disease severity of Nana 11 400-fold dilution treatment was 18%. There was a significant difference of 5% between both. In the field disease management experiment, the control group had a disease severity of 16% on the 77th day after the treatment of Doritaenopsis Mount Lip 'Chou', and the disease severity of Nana 11 400-fold dilution treatment was 3%. There was a significant difference of 5% between both. The above results showed that B. amyloliquefaciens Nana 11 400-fold dilution might be a promising biocontrol agent for preventive application, which conducted once a week for 4 times, to reduce the occurrence of Phalaenopsis yellowing leaf.