为寻找有效防治烟草黑胫病的生物材料,采用生长速率法和抑菌圈法测定了3种芸薹属植物提取液和3种异硫氰酸酯类制剂对烟草疫霉菌菌丝的抑制作用。结果表明:①与对照相比,不同浓度的芸薹属芜菁、芥菜和油菜提取液均显著抑制烟草疫霉菌菌丝的生长,EC50值分别为11.39、9.18和5.88 mg/mL,油菜提取液对烟草疫霉菌菌丝生长的抑制效应最佳。②与对照相比,不同浓度的异硫氰酸烯丙酯(AITC)和甲基异硫氰酸酯(MITC)制剂也均显著抑制烟草疫霉菌菌丝的生长,EC50值分别为2.07和4.44 mg/L,AITC对烟草疫霉菌菌丝生长的抑制效应最佳;而异硫氰酸苯酯(PITC)对烟草疫霉菌菌丝生长无明显的抑制作用。可见,3种芸薹属植物和2种异硫氰酸酯类制剂(AITC和MITC)对烟草疫霉菌具有较好的生防效应。
To obtain effective biological materials against tobacco black shank (Phytophthora parasitica var. nicotianae), the inhibition effects of three brassica extracts and three isothiocyanates on P. parasitica var. nicotianae were detected by mycelium growth rate method and inhibition zone method. The results showed that:Comparing with the control, 1) three brassica extracts (Brassica rapa L., Brassica juncea L. and Brassica campestris L.) at different concentrations significantly inhibited the mycelial growth of P. parasitica var. nicotianae with the EC50 values of 11.39, 9.18 and 5.88 mg/mL, respectively. Brassica campestris L. extract had an optimal inhibition effect on the mycelial growth of P. parasitica var. nicotianae. 2) Allylisothiocyanate (AITC) and methylisothiocyanate (MITC) at different concentrations also significantly inhibited the mycelial growth of P. parasitica var. nicotianae with the EC50 values of 2.07 and 4.44 mg/mL, respectively. AITC had a better inhibition effect on the mycelial growth of P. parasitica var. nicotianae; however, PITC had no inhibition effect on the mycelial growth of P. parasitica var. nicotianae. In conclusion, three brassica extracts and two isothiocyanates (AITC and MITC) could effectively control P. parasitica var. nicotianae.