Biological response of rat fed diets with high tuber content of conventionally bred and transgenic potato resistant to necrotic strain of potato virus (PVYN) Part I.: Chemical composition of tubers and nutritional value of diets

In experiments on rats, nutritional properties of a diet with high content (.40%) of potato tubers obtained from conventional or genetically-modified potato were determined. The potato cultivar Irga was transformed with viral genome sequences in order to improve its resistance to a necrotic strain of potato virus Y (PVYN). Four lines of genetically-modified potato were compared with non-transgenic somaclone from cv. Irga and three conventional cultivars Irga, Maryna and Ania. Potato tubers were autoclaved, dried and introduced to the diets which contained similar amount of protein (levelled through small addition of casein), fat, minerals and vitamins. Genetic modification of potato had no effect on the chemical composition (e.g. crude protein, starch, dietary fibre content and amino acid composition of protein) and nutritional properties of tubers (diet intake, animal growth, protein utilisation). Higher differences between chemical composition (especially in crude protein and starch content) and biological response of rats were determined in the case of diets containing tubers from conventional potato cultivars Ania, Maryna and Irga. Obtained results indicate that transgenic potatoes with genetically improved resistance to PVYN are substantial and nutritional equivalence to the non-transgenic cultivar. (c) 2004 Elsevier Ltd. All rights reserved.