Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Evaluation of natural and engineered resistance mechanisms in Solanum tuberosum for resistance to Phthorimaea operculella (Lepidoptera: Gelechiidae).

Abstract

Potato tuber moth (Phthorimaea operculella) is a highly destructive pest of cultivated potato and is responsible for damage to both leaf and tuber tissues. Host plant resistance is a central component to developing an integrated pest management program to control P. operculella. Studies were conducted to test the efficacy of a codon-modified CryV-Bacillus thuringiensis (CryV-Bt) gene constitutively expressed in potato and the combined effect of CryV-Bt expression with natural host plant resistance mechanisms in potato. Lemhi Russet and 2 lines with host plant resistance mechanisms, USDA8380-1 (leaf leptines) and L235-4 (glandular trichomes), along with the CryV-Bt-transgenic lines of each of these 3 genotypes were examined. Detached leaf bioassays were conducted to examine control of P. operculella. Nontransformed Lemhi Russet and L235-4 were susceptible to P. operculella while 54% mortality was observed when first-instar larvae were fed on USDA8380-1 leaves. High levels of expression occurred in the CryV-Bt transgenic lines, with up to 96% P. operculella mortality. These transgenic lines provide a germplasm base to examine combined insect resistance mechanisms as a means to achieve durable host plant resistance.