Screening Of Biocontrol Agents Salvia Root Rot

Salvia miltiorrhiza Bunge is a traditional bulk herbs,with the expansion of planting area and the extension of planting time,the phenomenon of pest and disease is more serious.In order to effective control the Salvia root rot disease,selected 10 kinds of high efficiency and low toxicity of the commercially available biocides,with carbendazim as chemical control and sterile water or water as control.To selecte one or several biopesticides,which has significant control effect for Salvia root rot disease and is non-toxic and green.To solve Salvia root rot disease,designed toxicity determination experiment and pot experiment,getting the following main conclusions.1、 Dentification of Salvia miltiorrhiza root rot pathogen Based on the observation results of the colony morphology, the results of the tieback test and the r DNA-ITS sequence analysis, the pathogen of the root rot of Salvia miltiorrhiza was identified as F. solani.2、Toxicity determination The results show: The first, there was a positive correlation between the concentration and the inhibition rate. The inhibition rate increased with the increase of the concentration, but the inhibition rate was significantly different between different reagents. Allitridi, phenazine-1-carboxylic acid, Bacillus subtilis, Trichoderma,Pseudomonas fluorescens bacteria and carbendazim have better antibacterial effect, and Harz Trichoderma, kasugamycin followed, Zhongshengmycin, polyoxin and agricultural antibiotic inhibiting effect is not obvious. Second, the size of the EC50 value is a measure of an important indicator of germicide size, the smaller the EC50 value, the stronger the agent virulence. Each agent EC50 steeled followed by Bacillus subtilis 7.17×10-7 g/ml<Carbendazim8.15×10-5 g/ml < Pseudomonas fluorescens bacteria 1.17×10-4 g/ml<phenazine-1-carboxylic acid 0.00033 g/ml <Trichoderma 0.00409 g/ml<Allitridi 0.028 g/ml<kasugamycin 0.034g/ml<Harz Trichoderma 0.064 g/ml<Zhongshengmycin 0.12 g/ml<agricultural antibiotic0.169 g/ml<polymyxin 0.33 g/ml. Therefore toxicity determination virulent agents are Bacillus subtilis, Pseudomonas fluorescens bacteria, phenazine-1-carboxylic acid,Trichoderma; Allitridi, kasugamycin, Harz Trichoderma followed; Zhongshengmycin,agriculture anti, polymyxin germicide weakest. Moreover, Bacillus subtilis was more virulent than carbendazim, and the antibacterial effect was more obvious.At the same time,Pseudomonas fluorescens bacteria, phenazine-1-carboxylic acid, Trichoderma also significantly inhibited the growth of F. solani.3、Salvia root rot pathogen control effect in pot experiment 11 different drug control effect in descending order Bacillus subtilis 216.73%, phenazine-1-carboxylic acid 150.04%,Pseudomonas fluorescens bacteria 149.96%, carbendazim 137.06%, kasugamycin 137.06%,Trichoderma 136.98%, Allitridi 118.53%, agricultural antibiotic 76.14%, polymyxin 52.36%,Harz Trichoderma 25.96%, Zhongshengmycin 16.65%. So,Bacillus subtilis, phenazine-1-carboxylic acid, Pseudomonas fluorescens bacterium control effect are better than carbendazim and may be considered to promote the field. Kasugamycin, Trichoderma and Allitridi followed, but also higher than 100%. Agricultural antibiotic, polymyxin, Harz Trichoderma,Zhongshengmycin control effect is the worst and not recommended.Comprehensive analysis toxicity experiment and pot experiment, Bacillus subtilis,phenazine-1-carboxylic acid and Pseudomonas fluorescens bacterium not only have a significant inhibitory effect for pathogen F. solani outside the plant system, but also have significant control effect to infected plants, it is recommended to further the field efficacy trials.