Characterisation and toxicity of Bacillus thuringiensis strains from hazelnut pests and fields.
BACKGROUND
In order to find and identify more toxic insecticidal Bacillus thuringiensis Berliner (Bt) strains, a survey was carried out of B. thuringiensis isolate pests belonging to Coleoptera, Lepidoptera and Diptera and from soils in hazelnut fields. Of 16 isolates having Bacillus cereus-B. thuringiensis morphology, eight were classified as B. thuringiensis because of the production of parasporal delta-endotoxin crystals.


RESULTS
In this study, eight isolates of B. thuringiensis from hazelnut pests (isolates Bn1, Mm2, Mnd and Xd3) and from hazelnut soils (isolates 6, 27, 40 and 46) have been characterised in detail. These isolates were compared with reference strains by electron microscopy, SDS-PAGE analysis, cry gene content, serological test and insecticidal activity.


CONCLUSIONS
Results indicate that Bn1 and MnD are B. thuringiensis subsp. kurstaki, and Mm2 and Xd3 are B. thuringiensis subsp. tenebrionis. In addition, isolate 6 is B. thuringiensis subsp. israelensis, isolates 27 and 46 are B. thuringiensis subsp. kumamotoensis and isolate 40 is B. thuringiensis subsp. indiana. The four B. thuringiensis isolates from hazelnut pests may be valuable as biological control agents against coleopteran and lepidopteran insects.
Sezen
Kazim
K
Department of Biology, Karadeniz Technical University, Trabzon 61080, Turkey. sezen@ktu.edu.tr
Kati
Hatice
H
Muratoglu
Hacer
H
Demirbag
Zihni
Z
D000818:Animals; D001413:Bacillus thuringiensis / Q000145:classification / Q000235:genetics / Q000502:physiology* / Q000648:ultrastructure; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics; D031211:Corylus; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D004731:Endotoxins / Q000235:genetics; D006460:Hemolysin Proteins / Q000235:genetics; D007313:Insecta / Q000382:microbiology*; D008854:Microscopy, Electron; D010572:Pest Control, Biological / Q000379:methods*; D012698:Serologic Tests
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis