The Present and Future Role of Insect-Resistant Genetically Modified Potato Cultivars in IPM

Potato, Solanum tuberosum L., is one of the world’s principal food crops. Important potato insect pests include Colorado potato beetle, Leptinotarsa decemlineata Say, potato tuberworm, Phthorimaea operculella (Zeller), and aphids, especially as they transmit potato leafroll virus and potato virus Y. Management of insect pests of potato relies almost entirely on chemical insecticides. Potato breeding is complicated by the potato’s tetraploidy. Numerous Solanum spp. have resistance to insects but these properties have not been transferred into commercially desirable cultivars. Insect-resistant cultivars are generally not available. GM potatoes expressing resistance to L. decemlineata, potato virus Y, and potato leaf roll virus were registered and marketed in the USA from 1995–2000, but were withdrawn from the market in response to marketing concerns about GM crops. Bacillus thuringiensis (Bt) genes for resistance to various insect pests are likely candidates for inclusion into potatoes using genetic engineering. Other resistance factors, including glandular trichomes, leptine glycoalkaloids, and other genes encoding for insecticidal proteins also show promise, especially if pyramided with appropriate Bt genes. Re-introduction of GM potatoes in the USA and elsewhere awaits changes in consumer preferences.