| dc.description.abstract | Arasbaran natural ecosystems are among the most diverse in the Iran. For this reason, we isolated strains of the entomopathogenic bacteria Bacillus thuringiensis (Bt) to determine their diversity, distribution and abundance. A total of 62 Bacillus thuringiensis strains were isolated from 150 soil samples collected from the five macroregions of the Arasbaran. The characterization of the strain collection provided useful information on the ecological patterns of distribution of B. thuringiensis and opportunities for the selection of strains to develop novel bioinsecticidal products. PCR analysis was applied to identify isolates harboring different cry type genes. Forty seven percent of the strains amplified with the cry 1 primer, 29% with cry 3 and 13% with cry 4. A total of 21 strains did not amplify with any of the cry primers used: cry 1, cry 3 and cry 4. Nine different genetic profiles were found; while, two of the 62 Bt isolates were harboring a combination of different cry genes, such as V-F-8-5 harbored lepidoptera-active cry 1Aa, coleoptera-active cry 3 gene and diptera active cry 4 gene. These profiles of cry genes indicate that V-F-8-5 isolate was active against lepidopteran, coleopteran and dipteran insects. é IDOSI Publications, 2012. | |
