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期 刊 ：植物保护学报 2008年

关键词：内生真菌；紫杉木霉；稻瘟病菌；附着胞；致病性；

Keywords:endophytic fungi, Trichoderma taxi, Magnaporthe oryzae, appressorium, pathogenicity,

摘 要 ：通过菌丝生长速率法和悬滴法测定ZJUF0986活性代谢产物对稻瘟病菌菌丝生长、孢子萌发和附着胞形成的影响。结果表明,ZJUF0986活性代谢产物对稻瘟病菌菌丝生长的有效中浓度EC₅₀为18.55mg/L,与对照药剂三环唑的EC₅₀(17.30mg/L)相比无显著性差异。活性代谢产物不仅影响孢子萌发,也显著降低附着胞的形成。浓度为10mg/L的活性代谢物可完全抑制孢子萌发及附着胞的形成;浓度为1.25mg/L时则明显延缓孢子萌发及附着胞的形成,处理48h后的孢子萌发率和附着胞形成率分别为62.17%和38.46%。以浓度为1.25mg/L活性代谢产物处理的稻瘟病菌孢子悬浮液接种离体大麦叶片,病原菌孢子在大麦叶片表面能部分萌发形成附着胞,但侵染栓形成延迟,致病性明显降低。

Abstract:The effect of ZJUF0986 bioactive metabolite on mycelium growth, spore germination and appressorium formation of the rice blast fungus, Magnaporthe oryzae, was tested with mycelium growth rate method and hanging drop method. EC₅₀ of ZJUF0986 bioactive metabolite against mycelium growth was 18.55mg/L, and 17.30mg/L in the control fungicide tricyclazole group. There was no significant difference between the two groups. ZJUF0986 bioactive metabolite not only depresses spore germination but also decrease appressorium formation. Spore germination and appressorium formation were inhibited completely when treated with 10mg/L ZJUF0986 bioactive metabolite. Spore germination and appressorium formation were delayed significantly when treated with 1.25mg/L ZJUF0986 bioactive metabolite, the rate of spore germination and appressorium formation after 48h was 62.17% and 38.46%, respectively. Barley leave inoculation in vitro with spore suspension, treated by 1.25mg/L ZJUF0986 bioactive metabolite, showed that spores of M.oryzae partially germinated and appressorium formatted, but invasion plug formation was delayed and pathogenicity deceased significantly.

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