Abstract
This study aimed at characterizing the insecticidal genes of eight
Bacillus thuringiensis
isolates that were recovered from the local environment of western Saudi Arabia. The screening for the presence of lepidopteran-specific
cry1A
family and
vip3A
genes, dipteran-specific
cry4
family and coleopteran-specific
cry3A
,
vip1A
and
vip2A
genes, was carried out by PCR. All eight isolates produced PCR products that confirmed the presence of
cry1Aa
,
cry1Ab
,
cry1Ac
,
cry4A
,
cry4B
genes, but not
cry3A
,
vip1A
and
vip2A
genes. However, three isolates only were found to carry
vip3A
genes as revealed by PCR. The observation of
cry1
and
cry4
genes suggests that these eight isolates may have dual activity against Lepidoptera and Diptera species, while three isolates possessed
vip3
genes in addition to
cry1
and
cry4
which suggests that these three isolates have toxic crystals and vegetative proteins. The results of this study are interesting in the sense that they may help developing new strategies for controlling insects of economic and medical importance in Saudi Arabia, using
B. thuringiensis
strains that naturally exist in the local environment instead of the current control strategies that are based solely on chemical insecticides.