Molecular characterization of Bacillus thuringiensis using rep-PCR

The genetic divergence of 65 strains of Bacillus thuringiensis (Bt) was determined using Rep-PCR. Based on the repetitive sequences the BOX primer was the most informative with 26 fragments, followed by ERIC (19) and REP (10), generating a total of 55 fragments. The dendogram shows that ten groups were formed when 45% was the average distance of the population: group 1 with 41,5% of the isolates, 33,8% of the isolates were distributed in other groups and 24,6% did not formed distinct group. 53,2% of the isolates from Embrapa are in the group 1, and 29,8% of the isolates are distributed in other groups. Bt strains from USDA and Institute Pasteur showed more variability.