The ability of the potato cyst nematode Globodera rostochiensis Woll. to reproduce in the roots of potato plants from the family Commersoniana (Solanum commersonii Dun., Uruguayan potato) was investigated. The results showed that G. rostochiensis juveniles are able to infest and develop in the roots of S. commersonii. The values of the nematode infection in individual plants varied from 98 to 171 cysts. Analysis of the “quality” of cysts indicated that the viability of eggs and juveniles was low due to high mortality of juveniles (J1) inside the eggs, as well as the presence of a large number of blastomere eggs
(eggs lacking vitelline fluid but with well-developed eggshells; eggs containing only vitelline fluid but no larva) and dead juveniles (J2) that hatched from eggs but did not emerge from cysts. The low value of G. rostochiensis multiplication factor indicates a reduced reproductive ability of the nematode during its development in S. commersonii roots. The results may be due to the geographical and environmental features of the distribution area of the plants, which define their physiological and biochemical state (non-genetic resistance), affecting the success of nematode parasitism.