Submitted to: American Journal of Potato Research
Publication Type: Peer reviewed journal
Publication Acceptance Date: 9/20/2010
Publication Date: 2/23/2011
Citation: Douches, D.S., Coombs, J., Lacey, L.A., Felcher, K., Pett, W. 2011. Evaluations of transgenic potatoes for resistance to potato tuberworm in the laboratory and field. American Journal of Potato Research. 88:91-95. Interpretive Summary: The potato tuber worm (PTW) is a world-wide pest of potato in the tropics and subtropics where potatoes are grown, it is considered the most damaging insect pest of potato, especially in rustic storage. It has recently become a serious pest of potato in the Pacific Northwest of the United States. A wide variety of chemical insecticides are used against PTW during the growing season but are not permitted to be applied just before harvest or in storage. Scientists at Michigan State University (MSU), East Lansing, MI and the USDA-ARS laboratory in Wapato, WA have investigated the use of potatoes that have been engineered to produce an insecticidal protein found in a bacterium that specifically kills moth larvae including larvae of PTW. They demonstrated the effectiveness of the engineered potato for killing larvae before they can infest potato plants and tubers. Use of this variety of potato could have a large impact on the reduction of pesticides in the environment and on the safety to applicators and other farm workers and the food supply. Colleagues at MSU separately demonstrated the complete lack of effect of this potato variety on the health of beneficial organisms such as honey bees and predators and other natural enemies of pest insects.
Technical Abstract: The potato variety ‘Spunta’ was previously transformed to constitutively express the cry1Ia1 gene from Bacillus thuringiensis from which three transgenic lines (Spunta G2, Spunta G3 and Spunta 6a3) were chosen to evaluate for resistance to potato tuberworm (Phthorimaea operculella Zeller). Because potato tuberworm is becoming a serious pest in the Pacific Northwest of the United States, ‘Spunta G2’, ‘Spunta G3’ and ‘Spunta 6a3’ were evaluated in Washington State through laboratory and field experiments. In the laboratory, both choice and no-choice experiments demonstrated that the transgenic ‘Spunta’ lines were completely resistant (100% mortality) to potato tuberworm. Potato tuberworm resistance was further supported by choice, field-cage studies in which the transgenic ‘Spunta’ lines harbored no potato tuberworm larvae at any sampling date while the controls were heavily infested (averaging 6.4 to as many 17.0 larvae per stem). These results indicate that the cry1Ia1 gene could be an effective component of potato tuberworm management in the Pacific Northwest as well as the international venues where it has already been proven effective.