Pepino (Solanum muricatum) is the only cultivated member of Solanum section Basarthrum. It is a popular crop in the Andean region, where it is cultivated for its juicy and aromatic fruits. Relatively little breeding has been done with this crop, but the studies done indicate the possibility of developing new improved cultivars. Breeding work to date has exploited the huge intraspecific diversity for many characters of agronomic value such as yield, fruit shape and color, or disease resistance. On the other hand, improvements in fruit quality (mostly sugar content) have been limited. Achievement of a higher organoleptic quality is essential for the success of this crop in markets of developed countries. The study of the taxonomy, phylogenetic relationships, morphological and molecular characteristics of wild species from Solanum section Basarthrum has opened the way to using the variation from these species, particularly interesting for their high sugar content, in breeding for fruit quality in pepino. In particular, the studies that showed that S. caripense and S. tabanoense are the closest wild species to the pepino, and that interspecific hybrids are fertile, led to the use of these species in breeding programmes. The results obtained after much backcrossing show that it is possible to transfer alleles for high sugar content from these wild species into the cultivated pepino. Furthermore, because only limited variation from wild Solanum section Basarthrum has been exploited, the perspectives for future improvements of cultivated pepino in general are very promising.

Key words: new crops, section Basarthrum, Solanum muricatum, wild relatives