芋艿采后主要病原菌分离鉴定及桧木醇抑菌效果

Identification of Dominant Postharvest Pathogens of Taro and Antifungal Activity of Hinokitiol against Them

为明确芋艿采后腐烂的主要病原菌种类,研究桧木醇对病原菌的抑制效果,为采后病害防治提供依据。本实验通过组织分离法,从采后自然发病的奉化芋艿上分离纯化主要病原真菌,基于科赫氏法则,进行病原菌致病性检测,并通过形态观察和真菌rDNA-ITS序列分析对病原菌进行鉴定;在此基础上进一步探讨桧木醇对病原菌的抑制效果,研究桧木醇对病原菌菌丝生长、孢子萌发、丙二醛浓度、亚细胞结构形态的影响。结果表明,贮藏过程中引起芋艿腐烂变质的主要病原菌经鉴定为镰刀菌属(Fusarium sp.)和可可毛色二孢菌(Lasiodiplodia theobromae);桧木醇处理可抑制此两种病原菌菌丝生长和孢子萌发,加剧菌丝膜脂过氧化,并破坏菌丝体亚细胞结构,抑菌效果明显,在控制芋艿采后病害方面具有较好的应用前景。

To provide evidence for the control of taro postharvest diseases,the main pathogens causing postharvest decay of taro and the antifungal effect of hinokitiol against these pathogens were investigated.In this study,the pathogenic fungal strains were isolated from naturally decaying taro grown in Fenghua,Zhejiang province by tissue separation method and identified by morphological characteristics and rDNA-ITS sequence analysis,and their pathogenicity was evaluated by Koch’s postulate.The antifungal activity of hinokitiol was investigated by evaluating its effects on the mycelial growth,spore germination,malondialdehyde content and ultrastructure of the dominant pathogens.The results showed that the two pathogenic strains isolated were identified as Fusarium sp.and Lasiodiplodia theobromae respectively.Hinokitiol exhibited obvious antifungal activity against the pathogens.It inhibited mycelial growth and spore germination,exacerbated membrane lipid peroxidation,and destroyed the subcellular structure of mycelia.Accordingly,this study indicated that hinokitiol can be a promising candidate for the control of postharvest diseases of taro.