小麦赤霉病复合天然抑菌剂的制备及其在小麦胚芽鞘上的验证

Preparation of Natural Compound Fungicide Against Fusarium graminearum and Its Verification on Wheat Coleoptiles

比较了肉桂醛、柠檬醛、香芹酚、芳樟醇、百里香酚、薄荷醇、紫苏醇对小麦赤霉病菌的体外抑菌效果,并进一步将香芹酚和百里香酚组合成复合天然抑菌剂。结果显示,当香芹酚和百里香酚质量比为1∶2时,抑菌剂对小麦赤霉病菌的体外抑制效果最佳,二者间具有协同作用。制备的抑菌剂能够改变病原菌细胞膜的通透性,并显著抑制被侵染小麦胚芽鞘上病斑的生长。

Antifungal effects of 7 different active components(cinnamaldehyde, citral, carvacrol, linalool, thymol,menthol, perillyl alcohol) from plant essential oils against Fusarium graminearum(F.g.) were compared by the method of inhibiting mycelial growth in vitro. Citral, carvacrol, and thymol were selected due to their lower EC50 values and formed a compound with each other, respectively. The compound composed of carvacrol and thymol was considered the most excellent pairing with the best inhibitory effect against F.g. in vitro. Additionally, the mass ratio of carvacrol and thymol in the compound was optimized and finalized the formulation of natural compound fungicide. Results showed that when the mass ratio of carvacrol and thymol was 1∶2, the fungicide had the best antifungal effect against F.g. and the synergistic index(S.I.) is 1.45, which showed a synergistic effect. The possible antifungal mechanisms of carvacrol and thymol compound were also analyzed. The prepared natural compound fungicide could change the permeability of F.g.’s cell membrane, reflected by the change in conductivity. Furthermore, the effects of the prepared natural compounded fungicide on wheat coleoptiles against F.g. were studied. It could significantly inhibit the growth of lesions on wheat coleoptiles. When fungicide(200 μg/mL) was administered to wheat coleoptiles infected by F.g., the control rate of the protective group and the curative group were 79.08% and 84.54%, respectively. This research provided a theoretical guidance for developing natural compound fungicides with precise efficacy. The possibility of further application of active components of plant essential oils was also discussed.