ISSN 2736-1756
Advanced Journal of Microbiology Research Vol. 2017
Available online at http://internationalscholarsjournals.org/journal/ajmr
© 2017 International Scholars Journals
Full Length Research Paper
Characterization and pathogenic evaluation of Bacillus thuringiensis isolates from West Azerbaijan province-Iran
Shahram Aramideh1*, Mohammad Hassan Saferalizadeh2, Ali Asghar Pourmirza2, Mahmuod Rezazadeh Bari3, Mansureh Keshavarzi4 and Mahdi Mohseniazar5
1Department of Plant Protection, institute Biotechnology, University of Urmia, Urmia, Iran.
2Department of Plant Protection, College of Agriculture, University of Urmia, Urmia, Iran.
3Department of Food Science, College of Agriculture, University of Urmia, Urmia. Iran.
4Seed and Plant Improvement Institute, Karaj, Iran.
5Department of Horticulture, College of Agriculture, University of Urmia, Urmia, Iran.
Accepted 2 June, 2016
Abstract
In order to find native strains of Bacillus thuringiensis, toxic to some agricultural pests, a survey was conducted in West Azerbaijan province. B. thuringiensis strains were isolated using acetate selection method with different concentrations. The morphology of crystals was studied using light microscopy. Bioassay tests were conducted on Culex pipiens (L.) as well as Pieris brassica (L.). Biochemical tests performed to identify the isolated strains. Based on the results, 48 B. thuringiensis strains were isolated from 740 samples. The best acetate concentration was determined as 0.25M (56.25%). Soil samples were the main source of B. thuringiensis (66%). Majority of strains (58%) had bipyramidal crystals. There was significant difference in toxicity to insects among B. thuringiensis isolates, 18.74 and 35.41% of the isolates were toxic to larvae of C. pipiens and P. brassicae, respectively, causing more than 50% mortality. B. thuringiensis subsp. kurstaki was the most common biochemical type (12 isolates = 25%). Results indicated that Bt isolates with insecticide activity could be used in integrated pest management to control agricultural and medical pests.
Key words: Bacillus thuringiensis isolate, Culex pipiens, Pieris brassica, Insecticidal activity