Association analysis between serotype, cry gene content, and toxicity to Helicoverpa armigera larvae among Bacillus thuringiensis isolates native to Spain

Identification and bioactivity of native strains of Bacillus thuringiensis from grain-related habitats in Turkey

“…In total, 23 different serovars were identified among 56 of the 84 motile strains (Table 1). Martinez et al (2005) reported 19 serovars among 178 B. thuringiensis strains native to Spain. Interestingly, serotypes were unevenly distributed through the collection, and one type, aizawai, was present in nearly 50% of the strains.…”

“…The PCR identification of cry1-type genes of 36 strains in the present study yielded 18 different profiles from the combinations of two to nine different cry1 genes (Table 2). Martinez et al (2005) analyzed 152 B. thuringiensis strains, native to Spain, based on 12 cry1 and one cry2 genes and they obtained 81 different profiles from combination of one to ten different genes. In another study from Colombia, Uribe et al (2003) reported 30 different profiles of 137 strains screened for 8 cry1-type genes, each harboring one to six different genes.…”

“…Taken together, these results indicate that the distribution of cry1 genes differs in collections depending on the origin of B. thuringiensis strains. Martinez et al (2005) and Martinez and Caballero (2002) reported that the distribution of cry1 genes somewhat correlated with particular serovars. They carried out statistical analysis to see the relation between serotype and cry1 gene frequency because the number of strains were relatively high for each type of cry1 gene, ranging from 8 to 80.…”

“…They are important for reflecting biodiversity through sampling sites and finding new strains with high toxicity against target insect species. Strains in the collections are characterized by a number of different methods to identify and to test and confirm their toxicity against different insect orders (Arango et al, 2002;Wang et al, 2003;Tamez-Guerra et al, 2004;Martinez et al, 2005). Identification of cry gene content by PCR is the most effective technique in screening large native collections to predict insecticidal activities of individual strains (Ben-Dov et al, 1997;Porcar and Juarez-Perez, 2002).…”

Characterization and Biological Activity of Bacillus thuringiensis Isolates that Are Potentially Useful in Insect Pest Control

“…The literature data report the possibility of using the whole-cell protein profile as a discriminating method with potency similar to RAPD with combined DNA patterns [1]. However, there is not always a good correlation between these factors and insecticidal activity of Bt strains [20,21]. In addition, there is a need to develop knowledge about the biological properties and diversity of Bt isolates since these data allow a better understanding of the biological factors that determine insecticidal properties.…”