caa a22 4500 477073522 CHVBK 20180405111433.0 cr unu---uuuuu 170330e19960601xx s 000 0 eng 10.1007/BF02764243 doi (NATIONALLICENCE)springer-10.1007/BF02764243 Selection and characterization of mexican strains of Bacillus thuringiensis active against four major lepidopteran maize pests [Elektronische Daten] [N. Bohorova, A. Maciel, R. Brito, L. Aguilart, J. Ibarra, D. Hoisington] Sélection et caractérisation d'isolats mexicains de Bacillus thuringiensis actifs contre quatre Lépidoptères majeurs du maïs In order to isolate novel delta-endotoxins fromBacillus thuringiensis Berliner, a total of 426 native isolates (in varying numbers for each pest) were screened against four major maize pests: corn earworm,Helicoverpa zea; fall armyworm,Spodoptera frugiperda; southwestern corn borer,Diatraea graridiosella, and sugarcane borer,Diatraea saccharalis. Spore-crystal complexes from the isolates were integrated into semi-artificial diets of each pest and mortality was assessed 7 days after treatment. A total of 25 isolates were selected on the basis of highest larval mortality against at least one insect species. There was no correspondence of the most toxic isolates when tested against the four different insect species. Most of the 25 selected isolates caused higher toxicities against all four pests than the standard strain HD-1, regardless of not achieving 100% mortality in any bioassay.H. zea demonstrated the highest level of mortality (96%) and was susceptible to the largest number of isolates (98). None of the other insect species were found susceptible at levels greater than 60%. All the selected active strains were isolated from stored grain dusts (except for LBIT-167), and had bipyramidal crystals with Cry I-like proteins. Most isolates also formed an associated square (cubic) inclusion, with Cry Il-like proteins according to SDS-PAGE analysis of their parasporal bodies. The most active isolates will be subjected to further studies, in order to identify putative novel genes to be expressed in transgenic maize Lavoisier Abonnements, 1996 Bacillus thuringiensis nationallicence Helicoverpa zea nationallicence Spodoptera frugiperda nationallicence Diatraea grandiosella nationallicence Diatraea saccharalis nationallicence mortality nationallicence maize nationallicence Bohorova N. aut Maciel A. CIMMYT, Apdo, Postal 6-641, 06600, México, D.F., México aut Brito R. CIMMYT, Apdo, Postal 6-641, 06600, México, D.F., México aut Aguilart L. aut Ibarra J. CINVESTAV-IPN, Apdo, Postal 629, 36500, Irapuato, Gto., México aut Hoisington D. CINVESTAV-IPN, Apdo, Postal 629, 36500, Irapuato, Gto., México aut Entomophaga Springer Netherlands 41/2(1996-06-01), 153-165 0013-8959 41:2<153 1996 41 10526 https://doi.org/10.1007/BF02764243 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02764243 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Bohorova N. aut NATIONALLICENCE 700 1- Maciel A. CIMMYT, Apdo, Postal 6-641, 06600, México, D.F., México aut NATIONALLICENCE 700 1- Brito R. CIMMYT, Apdo, Postal 6-641, 06600, México, D.F., México aut NATIONALLICENCE 700 1- Aguilart L. aut NATIONALLICENCE 700 1- Ibarra J. CINVESTAV-IPN, Apdo, Postal 629, 36500, Irapuato, Gto., México aut NATIONALLICENCE 700 1- Hoisington D. CINVESTAV-IPN, Apdo, Postal 629, 36500, Irapuato, Gto., México aut NATIONALLICENCE 773 0- Entomophaga Springer Netherlands 41/2(1996-06-01), 153-165 0013-8959 41:2<153 1996 41 10526 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer