Antifungal activity of Bacillus thuringiensis strains and their efficacy against the cotton leaf worm Spodoptera littoralis |
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| Authors: | Abeer M Mohammad Monira M El-Fatih Karima G Helmy |
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| Institution: | 1. Plant Protection Institute, Agricultural Research Centre, Giza, Egypt.abdallah_yousuf@yahoo.com;3. Plant Protection Institute, Agricultural Research Centre, Giza, Egypt.;4. Faculty of Agriculture, Plant Pathology Department, Ain Shams University, Kaliobiya, Egypt. |
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| Abstract: | Bacillus thuringiensis strains that belong to B. thuringiensis, B. kurstaki and soil-isolated B.t. were assessed in the following phytopathogenic: Rhizoctonia solani, that had their mycelial growth decreased after incubation in the presence of the bacterial strains. The bacteria have also pathogenic effect against the insect pest Spodoptera littoralis. The isolate B.t. D-1 and the B.t. kurstaki HD-203 were found to be inhibiting R. solani, the strain B. kurstaki HD-203 displayed the highest percentage of inhibition (64%) and B.t. D-1 showed 49% of inhibition. Antagonistic activity was maintained up to pH 8.5, and the antifungal activity was stable to heat at 70?°C for 1?h. Minimal inhibitory concentrations were 152 and 131?μl/ ml for B.t. D-1 and B. kurstaki HD-203, respectively. The two strains also have high efficacy against S. littoralis larvae, B.t. D-1 gave 70% and the B. kurstaki HD-203 strain gave 80% mortality after seven days of treatment. |
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| Keywords: | Bacillus thuringiensis B kurstaki Rhizoctonia solani Spodoptera littoralis |
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