[Objective] The paper was to screen the biocontrol agents with good control effects against tobacco bacterial wilt. [Method] The strains with antagonistic activity against tobacco bacterial wilt were isolated from 36 ...[Objective] The paper was to screen the biocontrol agents with good control effects against tobacco bacterial wilt. [Method] The strains with antagonistic activity against tobacco bacterial wilt were isolated from 36 copies of rhizosphere soil sample. The strain with best inhibition effect was identified, and carried out pot test and growth-promoting experiment. [Result] The strain with best inhibtion effect was Tra69, which was identified to be Streptomyces flavogriseus. The fermentation liquid of Tra69 had good control effect against Ralstonia solanacarum, and also had good growth-promoting effect on tobacco. [Conclusion] Tra69 was the biocontrol agent with excellent control effect against R. solanacarum, which could be further developed and used in biological control against tobacco diseases.展开更多
[Objective] This study was conducted to investigate the biocontrol activity of Streptomyces corchorusii strain NF0919 and Bacillus subtilis D J-6 WP to grape downy mildew. [Methed] We determined the indoor toxicity of...[Objective] This study was conducted to investigate the biocontrol activity of Streptomyces corchorusii strain NF0919 and Bacillus subtilis D J-6 WP to grape downy mildew. [Methed] We determined the indoor toxicity of the supernatant of S. corchorusii strain NF0919, 1.0×1011 cfu/g B. subtilis D J-6 WP, mancozeb and dimethomorph on Plasmopara viticola by the leaf disc method, respectively, and a field efficacy trial was conducted. [Result] The results showed that the ECso values of the supernatant of strain NF0919, 1.0×1011cfu/g B. subtilis D J-6 WP, mancozeb and dimethomorph were 96.285 9, 86.603 8, 69.947 2 and 7.263 6 μg/ml, respec- tively. The values of field efficacy in preventive experiments for grape downy mildew on the 7th day after 2 times of spraying 20 times diluent of the supernatant of strain NF0919 and 1 000 times diluent of 1.0×1011 cfu/g B. subtilis D J-6 WP were 71.55% and 70.71%, respectively, and the values of field efficacy on the 14th day after the 2 times of fungicide application were 67.54% and 68.19%, respectively. The values of field efficacy in curative experiments on the 7th day after 2 times of spraying 20 times diluent of the supematant of strain NF0919 and 1 000 times diluent of 1.0×1011 cfu/g B. subtilis D J-6 WP were 59.72% and 56.07%, respectively, and the val- ues of field efficacy on the 14th day after the 2 times of fungicide application were 56.88% and 57.46%, respectively. The field efficacy values of the 2 tested biocon- trol agents were equivalent. The protective effect showed no significant difference between each of tested biocontrol agents and 300 times diluent of 50% mancozeb WP, but there was a significant difference in the efficacy between each of tested biocontrol agents and 200 times diluent of 40% dimethomorph SC. [Conclusion] The S. corchorusii strain NF0919 and B. subtilis D J-6 WP had certain biocontrol poten- tial to grape downy mildew and development value.展开更多
基金Supported by Key Science and Technology Project of Hubei Tobacco Company(027Y2012-083)
文摘[Objective] The paper was to screen the biocontrol agents with good control effects against tobacco bacterial wilt. [Method] The strains with antagonistic activity against tobacco bacterial wilt were isolated from 36 copies of rhizosphere soil sample. The strain with best inhibition effect was identified, and carried out pot test and growth-promoting experiment. [Result] The strain with best inhibtion effect was Tra69, which was identified to be Streptomyces flavogriseus. The fermentation liquid of Tra69 had good control effect against Ralstonia solanacarum, and also had good growth-promoting effect on tobacco. [Conclusion] Tra69 was the biocontrol agent with excellent control effect against R. solanacarum, which could be further developed and used in biological control against tobacco diseases.
基金Supported by Science&Technology Specific Project for Enriching People and Strengthening County Economy in China(BN20156222)Jiangsu Agricultural Science and Technology Independent Innovation Fund(CX(14)2056)
文摘[Objective] This study was conducted to investigate the biocontrol activity of Streptomyces corchorusii strain NF0919 and Bacillus subtilis D J-6 WP to grape downy mildew. [Methed] We determined the indoor toxicity of the supernatant of S. corchorusii strain NF0919, 1.0×1011 cfu/g B. subtilis D J-6 WP, mancozeb and dimethomorph on Plasmopara viticola by the leaf disc method, respectively, and a field efficacy trial was conducted. [Result] The results showed that the ECso values of the supernatant of strain NF0919, 1.0×1011cfu/g B. subtilis D J-6 WP, mancozeb and dimethomorph were 96.285 9, 86.603 8, 69.947 2 and 7.263 6 μg/ml, respec- tively. The values of field efficacy in preventive experiments for grape downy mildew on the 7th day after 2 times of spraying 20 times diluent of the supernatant of strain NF0919 and 1 000 times diluent of 1.0×1011 cfu/g B. subtilis D J-6 WP were 71.55% and 70.71%, respectively, and the values of field efficacy on the 14th day after the 2 times of fungicide application were 67.54% and 68.19%, respectively. The values of field efficacy in curative experiments on the 7th day after 2 times of spraying 20 times diluent of the supematant of strain NF0919 and 1 000 times diluent of 1.0×1011 cfu/g B. subtilis D J-6 WP were 59.72% and 56.07%, respectively, and the val- ues of field efficacy on the 14th day after the 2 times of fungicide application were 56.88% and 57.46%, respectively. The field efficacy values of the 2 tested biocon- trol agents were equivalent. The protective effect showed no significant difference between each of tested biocontrol agents and 300 times diluent of 50% mancozeb WP, but there was a significant difference in the efficacy between each of tested biocontrol agents and 200 times diluent of 40% dimethomorph SC. [Conclusion] The S. corchorusii strain NF0919 and B. subtilis D J-6 WP had certain biocontrol poten- tial to grape downy mildew and development value.
