珍珠相思叶状柄水提物的化感效应研究

    Isolation and inhibitory activity of endophytic fungi from the Semi-mangrove plant Myoporum bontioides A. Gray

    • 摘要: 探讨不同浓度珍珠相思叶状柄的水提液对3 种茄科植物(番茄、茄子和辣椒)生长的影响。通过种子萌发试验,测定不同浓度叶状柄水提液对受体植物的化感效应指数、萌发率和幼苗生长特性影响,分析是否存在化感效应和潜在的生态风险。低浓度(0.02 g/mL)叶状柄水提液条件下,茄子种子萌发率的化感指数为0.06;番茄的芽长化感效应指数和综合指数分别为0.37、0.09,而较低浓度(0.04 g/mL)下分别为0.30 和0.01,表现为一定的促进作用;此外的其他指数均为负值,体现出较强的抑制作用。叶状柄水提液中所含的化感物质对3 种茄科植物种子萌发及幼苗生长表现有所不同。不同浓度水提液对番茄幼苗生长具有低促高抑的双重浓度效应,而对辣椒和茄子幼苗生长均具明显的抑制作用,且在其作用范围内具有浓度依赖性。

       

      Abstract: To search for new microorganisms with inhibitory activity against plant pathogens, Myoporum bontioides A. Gray was chosen to be studied. One hundred and four endophytic fungal cultures were isolated from the leaf , leaf vein, stem, bark, and root samples of Myoporum bontioides A. Gray. They mainly belonged to the genera of sterile mycelium, Gloeosporium spp., Penicillium spp., Cladosporium spp. and Aspergillus spp. Primary bioassay of their metabolites showed that about 77.9% strains had inhibitory activity against at least one plant pathogens among Fusarium graminearum, Gloeosporium musae, Penicillium italicum and Phytophthora sojae (Kaufmann & Gerdemann). And the proportions of the strains with medium and high activity were ab out 42.3% and 11.5%, respectively. The HPLC analysis showed that the spectral profiles of the extracts of Myoporum bontioides A. Gray and five selective endophytic fungi with high antifungal activity were remarkably different, which suggested that these fungi produced different antifungal compounds in contrast to their mother plant.

       

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