There are, however, some slight morphological changes, which are attributed to somaclonal variation. The natural exchange of genetic material is only possible with other varieties of potato Solanum tuberosum . No natural genetic exchange has been found with wild relatives, Solanum nigrum and Solanum dulcamara . Very low frequency exchange has been detected with Solanum nigrum under forced hybridisation. Therefore the chances for successful hybridisation between transformed potatoes and other Solanum species are very unlikely.
Genetic spread is assessed as limited to cross-pollination with other potatoes.
In view of the presence of a bacterial promoter linked to the npt III gene, there is the potential for genetic transfer to microbes in the soil and other environments and expression in such backgrounds. There are no data provided to assess this risk or to relate it to the natural occurrence of resistance to relevant antibiotics in microbial populations in the soil. Dissemination is by tuber and seed over a limited distance. Potatoes have difficulty becoming established outside cultivated fields. These will be killed by frost, drought and standard agricultural practice in following crops.