“Caracterización molecular y morfología de los cristales de cepas de Bacillus nativas patógenas para Spodoptera frugiperda”

ANALÍA ALVAREZ; FLAVIA LOTO; CARLOS NIETO; LICIA PERA; EDUARDO VIRLA; MARIO BAIGORI

Huerta Grande; Córdoba

Congreso; I Reunión Conjunta de Sociedades de Biología de la República Argentina; 2007

Sociedades de Biología de la República Argentina

Introduction: Bacillus thuringiensis (Bt) are the microorganisms most widely used in biological control of insect pest. These bacteria produce entomopathogenic crystals (Cry) during sporulation showing different morphologies according to Bt strains. Objectives: To determine the morphology of crystals produced by three native Bt strains active against larvae of Spodoptera frugiperda (Sf) and to characterize the microorganisms molecularly. Materials and methods: Crystals were studied by scanning electron microscopy. Sporulated cells were removed from the agarized medium, washed and placed on a micro slide. The 16S rDNA gene was amplified from genomic DNA by PCR. Results and conclusions: Morphological observations showed that the three strains contained bipyramidal crystals of two different sizes. This feature may resemble those against lepidopteran targets. The 16S rDNA analysis identifies the isolations as B. thuringiensis subspecies. The sequences were deposited in the Gene Bank, access Nº: RT EF638795, LSM EF638796 and LQ EF638798. These results complement the knowledge on these native pathogenic strains with promissory characteristics for Sf biological control. Acknowledgments: PICTO-UNT 761, PIP 6062 and CIUNT 26/D308.