Bacillus subtilis Czk1挥发性化合物对橡胶树红根病菌的抑制作用

Inhibition of Volatile Organic Compounds Produced by Bacillus subtilis Czk1 on Red Root of Rubber Tree

由橡胶灵芝菌(Ganoderma pseudoferreum)引起的红根病是橡胶树生产上毁灭性病害之一。为明确枯草芽孢杆菌(Bacillus subtilis)Czk1产生的挥发性物质对橡胶灵芝菌的抑制作用,以橡胶灵芝菌为靶标菌,通过平板对峙法检测Czk1所产12种挥发性化合物纯品的抑菌活性;采用生长速率法对挥发性活性组分进行毒力测定;检测挥发性混合组分对橡胶灵芝菌细胞的形态及细胞膜通透性的影响。结果表明,12种挥发性化合物纯品对橡胶灵芝菌均具有不同程度的抑菌活性,其抑菌率在15.20%~100%之间,其中,苯甲醛对橡胶灵芝菌抑菌活性最强,抑菌率达到100%。9种化合物纯品对病菌的毒力测定中,苯甲醛、3,5-二甲氧基苯乙酮、2,6-二叔丁基对甲酚EC50分别为20.30、30.62、40.96μg·mL^-1。该三种混合组分浓度为25μg·mL^-1,其对橡胶灵芝菌的抑制率为67.00%。经三种混合活性组分处理后的病菌菌丝缠绕成一团,细胞壁变薄,部分膜结构不完整。混合活性组分影响病菌细胞通透性。Czk1产生的挥发性物质具良好的抑菌活性是由这些挥发性物质协同作用的结果,这些挥发性物质应用前景巨大,可作为化学农药替代品防治橡胶树红根病。

Red root is one of the most devastating diseases of rubber tree caused by Ganoderma pseudoferreum. In order to provide new materials for the prevention and control of red root disease of rubber trees, the inhibitory effect of volatile organic compounds produced by Bacillus subtilis Czk1 on Ganoderma pseudoferreum was investigated. In this study, G. pseudoferreum was used as the target fungus, and the antifungal activity of 12 kinds of pure volatile organic compounds produced by Czk1 was detected by pair culturing method. Virulence of the active volatile organic compounds was determined by the growth rate method. The effect of volatile organic compounds on morphology and cell membrane permeability of G. Pseudoferreum cells were detected. The results showed that the 12 volatile organic compounds had different degrees of antifungal activity against G. pseudoferreum, and their inhibition rate ranged from 15.2% to 100%. Among them, benzaldehyde had the strongest antifungal activity against pathogens, and the rate reached 100%. In the determination of the virulence of 9 pure compounds to pathogens, the EC50 of benzaldehyde, 3,5-dimethoxyacetophenone, and butylated hydroxytoluene were 20.30, 30.62, 40.96 μg·mL^-1, respectively. The concentration of the three mixed components was 25 μg·mL^-1, the inhibitory rate against G. pseudoferreum was 67.0%. The mycelia of pathogen were greatly twined, the cell wall became thinner, part of the membrane structure was incomplete and the permeability of pathogen cell was affected after treated with volatile organic compounds. The good fungistatic activity of volatile organic compounds produced by Czk1 was the result of the synergy of these volatile organic compounds. These volatile organic compounds had great application prospects and could be used as chemical pesticide substitutes to prevent and cure rubber tree root disease.