Survival of two strains of Phthorimaea operculella (Lepidoptera: Gelechiidae) reared on transgenic potatoes expressing a Bacillus thuringiensis crystal protein

Abstract

Two populations of Phthorimaea operculella (Zeller), one of them presumed to be resistant to Dipel (a com- mercial preparation of Bacillus thuringiensis delta-endotoxins), and the other susceptible, were grown on four cultivars of potatoes, two of them a first generation of transgenic plants, expressing the Bacillus thuringiensis Cry1Ab delta endo- toxin protein, and the other two untransformed. The moth population which was reported to be resistant, proved to have less mortality than the susceptible one, but it was not really resistant to Cry1Ab. The transgenic potatoes were partially protected against the attack of the moth. The adult survival of the two strains of Phthorimaea operculella reared on trans- genic potatoes was less than half their survival on untransformed potatoes, so that CrylAb expressing potato tubers proved to protect partially against attack of the moth. ( © Inra/Elsevier, Paris.) Phthorimaea operculella / Bacillus thuringiensis / transgenic potatoes / CrylAb Rsum -Survie de deux souches de Phthorimaea operculella (Lepidoptera : Gelechiidae) leves sur des pommes de terre transgniques exprimant la protine CrylAb de Bacillus thuringiensis. Deux populations de Phthorimaea operculella (Zeller), l'une suppose rsistante au Dipel™ (une prparation commerciale de delta-endo- toxines de Bacillus thuringiensis) et l'autre sensible, ont t cultives sur quatre cultivars de pomme de terre, deux transgniques de premire gnration, exprimant la protine CrylAb de Bacillus thuringiensis, et deux non transforms. La population de papillons considre comme rsistante a prsent une mortalit infrieure celle de l'autre population, mais n'tait pas vraiment rsistante CrylAb. Les pommes de terre transgniques taient en partie protges d'une attaque de l'insecte. La survie au stade adulte des deux souches de Phthorimaea leves sur les plantes transgniques tait au moins deux fois infrieure celle constate sur les plantes non transformes. Il en rsulte que les pommes de terre exprimant le gne cry1Ab sont partiellement protges des attaques du papillon. ( © Inra/Elsevier, Paris.) Phthorimaea operculella / Bacillus thuringiensis / pommes de terre transgniques / CrylAb