Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : Actividad insecticida de bacterias asociadas al cultivo de chile (Capsicum annuum L.) y aisladas del Anthonomus eugenii Cano como alternativa de control biológico en esta plaga

Auteur : Escobar Martínez, Perla Yunuen

Etablissement de soutenance : Centro de Investigaciones Biológicas del Noroeste (CIBNOR)

Grade : Maestría en Ciencias en el Uso, Manejo y Preservación de los Recursos Naturales 2008

Résumé
Pepper weevil, Anthonumus eugenii Cano is the major pest of papperes (Capsicum spp) in Mexico and other countries. Females oviposit inside the fruit, and it serves as feed during all their instars. It represents a problem since it is possible to lose a complete crop. Therefore it has been proposed to evaluate insecticidal activity of microorganisms in this biological model. From infested and not infested fruits sampled from different localities, the microbial community profile associated to fruit and insects was determined by SSCP. In order to evaluate the insecticidal activity, cultivable bacteria from both fruits and insects were isolated using traditional methods. A. eugenii insects at adult or larvae stadium were colleted, and their maintenance and reproduction conditions were established. In order to study the physiology of A. eugenii, the ontogenic variation of hidrolytic enzymes were evaluated by the API ZYM system. Differences in the microbial community profiles between infested and not infested fruits were observed. Moreover, the same differences were observed in fruits that were sampled from different localities. Finally in A. eugenii, the microbial community profiles were independent of the localities where them were sampled. Enterobacteriaceae and Bacillaceae were the dominant bacterial groups in both fruits and insects. It was possible to maintain A. eugenii in all instars at temperatures ranged between 22 to 25 °C without photoperiod. The enzymatic activity showed significative differences during the various larval stadiums of A. eugenii showing the highest activity at the L1 instar. Moreover, a strain of Bacillus cereus showed insecticidal activity against A. eugenni with 92% of mortality. Finally, two strains of Enterococcus faecium and Bacillus sp. were pathogens for A. eugenii causing modifications in the appearance of their feces.

Mots Clés : Picudo de Chile ; Actividad Insecticida ; Diversidad Bacteriana

Présentation

Version intégrale (3,41 Mb)