柠檬草精油对烟草黑胫病的抑制活性研究

Antimicrobial Activities of Lemongrass Essential Oil Against Phytophthora parasitica var. nicotianae

研究了5种常见植物精油的抗烟草黑胫病活性,确定了植物精油的种类与浓度,为烟草黑胫病防治的精油药剂的开发与应用提供理论依据。采用菌丝生长抑制法和茎秆接种法,分别评价了植物精油对烟草黑胫病的体外和体内抑菌活性。结果表明,在体外条件下,柠檬草精油对烟草黑胫病的抑制效果最好,具有浓度梯度抑制效应,最低抑菌浓度为320μg/mL;在体内条件下,柠檬草精油640μg/mL时对烟草黑胫病预防与治疗效果最佳,病情指数分别为16.67和56.79,相对诱导效果分别为81.93%和38.44%,与甲霜灵190μg/mL无显著性差异。柠檬草精油具有优越的体外和体内抗菌活性,是有潜力的生物抗菌剂和杀菌剂,有望在今后的烟草黑胫病菌防治中进一步开发利用。

Antimicrobial activities of five common plant essential oils against Phytophthora parasitica var. nicotianae were investigated,and the species and concentration of the plant essential oils were determined, which provided a theory basis for the development and application of essential oil fungicide against P. parasitica var. nicotianae. Hypha growth inhibition assay and stem inoculation method were used to evaluate the in vitro and in vivo antimicrobial activity of essential oils to P. parasitica var. nicotianae. The results showed that, in the selected five essential oils, lemongrass essential oil was most effective against P. parasitica vat. nicotianae in vitro which inhibited hypha growth in a dose-dependent manner, and totally inhibited mycelia growth with a minimum concentration of 320 μg/mL. In vivo, 640 μg/mL of lemongrass essential oil was most efficient for prevention and treatment of disease with a disease index of 16. 67 and 56. 79 and relatively induced efficiency of 81. 93% and 38. 44%, respectively. No significantdifference was found between 640 vg/mL of lemongrass essential oil and 190 vg/mL of metalaxyl. This study has demonstrated that the lemongrass essential oil is potential and promising antimicrobial agents which could be used as biofungicide in the protection of tobacco against Ph ytophthora parasitica vat. nicotianae.