Abstract:
Bacillus thuringiensis
strains were isolated from various soil samples co
llected from
different regions of Kahramanmara
ş
in Turkey and were characterized by their colony
morphology, PCR method with cryIAb/Ac, cryID, cry2
and cyt2 primers, and SDS-PAGE
of crystal proteins with 130-140 and 60-70 kDa mole
cular weights. Plasmid profiles of
selected isolates were also analyzed. Among the
cry
genes studied,
cry1Ab/Ac
was found to
be the most common one (60%
) in local isolates. Bioactivity tests were carried
out under
laboratory conditions to assess the efficacy of iso
lates against the third instar larvae of the
stored product insects;
Anagasta
kuehniella
and
Plodia interpunctella.
Toxicity values of
the isolates varied between 20.00-53.33%
for
A. kuehniella
and 20.00-55.56%
for
P.
interpunctella
at 1,000 μg g
-1
concentration. Out of 55 isolates, ST13.1 was foun
d to be the
most effective against
A. kuehniella.
Also, ST7.2, ST7.3, and ST8.2 isolates yielded
remarkable control against
P. interpunctella
. Further research is recommended to
investigate the efficacy of these promising
Bt
isolates against other pest insect species.
Keywords:
Bacillus thuringiensis
, Bioactivity,
Cry
gene, Stored product insects, Toxicity.
