Article

Wild relatives of our cultivated crops are an important source for the genetic improvement of these crops This paper describes the presence of wild relatives in the collections of Centre for Genetic Resources, the Netherlands (CGN). It shows that the collections differ substantiall y in the presence of wild relatives. It is demonstrated that former working collections of breeders are often dominated by cultivated materia!. This paper brieny reviews the utili zation of wild relatives of Solanum and Lactuca in breeding. Il is emphasized thal the evaluation of wild relatives for certain properties is a prerequisite for the utili zation of this materia!. Evaluation of wild relatives will also reveal the geographical distribution of specific characters in the originai collecting sites. Examples of the geographical distribution of wild potato species with resistance to economie pests and diseases are presented.