Field and storage evaluations of 'Spuntag2' for resistance to potato tuber moth and agronomic performance

Abstract

'SpuntaG2' is a transgenic potato (Solanum tuberosum) cultivar that contains the cry1Ia1 gene for resistance to potato tuber moth (Phthorimaea operculella), which is a serious pest of potato in many parts of the world. Previous studies have characterized 'SpuntaG2' at the molecular level and evaluated it for safety as a human food source. The objective here wasto determine the efficacyof'SpuntaG2' against the potato tuber moth in the field and in storage and to evaluate its agronomic performance. Efficacy trials at seven South African locations over 5 years indicated that 'SpuntaG2' gave complete control of potato tuber moth in the field and storage. The agronomic performance (tuber size and yield) of 'SpuntaG2' was not statistically different from 'Spunta' or was better than 'Spunta' at all locations/years with two exceptions. Three years of trials in Michigan further support these conclusions. Evaluations done during the 2006-07 South African season showed that 'SpuntaG2' did not differ from non-transgenic 'Spunta' for the following traits: maturity, growth habit, eye morphology, tuber size distribution, tuber shape, skin and flesh color, growth cracks, internal defects, specific gravity, chip color, cooking quality, disease resistance, and pollen fertility. Based on the results of these trials, it was concluded that 'SpuntaG2' provides the agronomic performance of 'Spunta' with the added benefit of resistance to potato tuber moth.