Evaluations of Transgenic Potatoes for Resistance to Potato Tuberworm in the Laboratory and Field

Abstract

The potato variety 'Spunta' was previously transformed to constitutively express the cry1Ia1 gene from Bacillus thuringiensis from which three transgenic lines (SpuntaG2, SpuntaG3 and Spunta6a3) 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, 'SpuntaG2', 'SpuntaG3' and 'Spunta6a3' 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.Resumen Se transformó previamente a la variedad de papa "Spunta" para que expresara constitutivamente el gen cry1Ia1 de Bacillus thuringiensis, de la cual se seleccionaron tres líneas transgénicas (SpuntaG2, SpuntaG3, y Spunta6a3) para evaluarles su resistencia a la palomilla de la papa (Phthorimaea operculella Zeller). Considerando que la palomilla de la papa se está convirtiendo en una plaga seria en el Pacífico Noroeste de los Estados Unidos, "SpuntaG2", "SpuntaG3", y "Spunta6a3" se evaluaron en el Estado de Washington en experimentos de laboratorio y campo. En el laboratorio, ambos, experimentos seleccionados y no seleccionados, demostraron que las líneas transgénicas de Spunta fueron completamente resistentes (100% de mortalidad) a la palomilla de la papa. La resistencia fue posteriormente respaldada por estudios de selección, en jaulas de campo, en donde las líneas transgénicas de Spunta no mantuvieron a las larvas de la palomilla en ninguna de las fechas de muestreo, mientras que los testigos estuvieron fuertemente infestados (promediando de 6.4 a tanto como 17.0 larvas por tallo). Estos resultados indican que el gen cry1Ia1 pudiera ser un componente efectivo en el manejo de la palomilla de la papa en el Pacífico Noroeste, así como a nivel internacional donde ya se ha probado que es efectivo.

Applications of biotechnology and genomics in potato improvement

“…Many such cry genes, when expressed in potato plants, have been shown to be highly effective in controlling PTM. Among them are cry 1Ab2 (Chakrabarti et al ., ), cry 1Ab5 (Cañedo et al ., ; Rico et al ., ), cry 1Ab6 (Jansens et al ., ) cry 1Ac1 (Ebora et al ., ), cry 1Ac9 (Davidson et al ., , ; Meiyalaghan et al ., ), cry 1Ia1 (Douches et al ., ; Li et al ., ), cry 1Ba1 and cry 1Ca5 (Meiyalaghan et al ., ). In addition to the cry 1 class, success has been achieved with the cry 9Aa2 gene (Jacobs et al ., ; Meiyalaghan et al ., , ).…”

Segregation and Efficacy of the <I>cry1Ia1</I> Gene for Control of Potato Tuberworm in Four Populations of Cultivated Potato

“…SpuntaG2 contains a single copy of the cry1Ia1 gene and has complete resistance to potato tuberworm (Rondon et al 2009, Douches et al 2010b). If SpuntaG2 is deregulated, it can be used as a source of potato tuberworm resistance for variety development without further regulatory analysis required for the resultant progeny.…”