生防菌D25与嘧环·咯菌腈复配对番茄灰霉病防治的增效作用

Synergistic Effect of a Biocontrol Bacterium D25 and Cyprodinil·Fludioxonil on the Control of Tomato Gray Mold

为了筛选获得生防菌D25与杀菌剂的复配制剂,降低杀菌剂用量并提高番茄灰霉病的防治效果,本文采用含毒介质法测定了12种杀菌剂对番茄灰霉病菌的室内毒力,并用平板计数法测定抑菌作用较好的杀菌剂与生防菌D25的生物相容性,采用毒性比率筛选出杀菌剂与生防菌D25复配的最佳比例,并通过盆栽试验进一步验证生防菌D25与杀菌剂复配对番茄灰霉病的防效。结果表明,12种杀菌剂中,枯草芽胞杆菌和哈茨木霉对番茄灰霉病菌的毒力最高,EC_(50)值分别为4.564×10^(-5)和0.021 mg/L。嘧环·咯菌腈对番茄灰霉病菌的毒力较强,EC_(50)值达0.043 mg/L。植物源杀菌剂香芹酚和苦参·蛇床素对番茄灰霉病菌的毒力最低,EC_(50)值分别为12.469和19.220 mg/L。生物相容性试验结果表明,嘧环·咯菌腈与生防菌D25有较好的生物相容性。0.043 mg/L嘧环·咯菌腈与7×10^(4)CFU/mL的生防菌D25以5:5体积比进行复配时,毒性比率可达1.3943,表现为增效作用。盆栽试验中预防处理组的防效达72.29%,比两种单剂的防效分别提高了19.26%和29.29%,治疗处理组的防效达61.57%,相比两种单剂的防效分别提高了15.40%和21.23%。综上所述,生防菌D25与嘧环·咯菌腈复配对番茄灰霉病菌具有增效作用,在不降低防病效果的情况下,可减少嘧环·咯菌腈的施药量达50%,具有很大应用潜力。

In order to screen the fungicide complex composed of biocontrol bacterium D25 and chemical fungicide to improve the biocontrol efficacy on tomato gray mold as well as reducing the dosage of chemical fungicides,toxicity of 12 fungicides against Botrytis cinerea was firstly tested in vitro by toxic medium method Bio-compatibility between fungicides with strong antifungal activity and biocontrol bacterium D25 was determined by plate counting method.Optimal ratio of fungicides and biocontrol bacteriun D25 was screened by the toxicity ratio,and control efficacy of the complex in suppressing tomato gray mold was further tested in pot experiment.The results showed that among 12 fungicides,Bacillus subtilis and Trichoderma harzianum had the strongest toxicity against B.cinerea,with EC_(50)values of 4.564×10^(-5)mg/L and 0.021 mg/L,respectively.Cyprodinil·fludioxonil had better toxicity,with EC_(50)value of 0.043 mg/L.Two botanical fungicides,carvacrol and matrine·osthol,had the lowest toxicity,with EC_(50)values of 12.469 mg/L and 19.220 mg/L,respectively.Biocompatibility test showed that no negative effect was found between cyprodinil·fludioxonil and bio-control bacterium D25.The complex of cyprodinil-fludioxonil(0.043 mg/L)and bio-control bacterium D25(7×10^(4)CFU/mL)at a volume ratio of 5:5performed synergistic effect,with the toxicity ratio of 1.3943.In the pot experiment,the control efficacy of the prevention group reached 72.29%,which was higher than that of the individual fungicide by 19.26%and 29.29%,respectively,while the control efficacy of the treatment group reached 61.57%,which was higher than that of the individual fungicide by 15.40%and 21.23%,respectively.In conclusion,combined application of bio-control bacterium D25 and cyprodinil·fludioxonil had a synergistic effect against B.cinerea,which reduced the application amount of cyprodinil·fludioxonil by 50%without reducing the control efficacy on tomato gray mold,and had great potential to be applied in field.