The incorporation of heteroduplex analysis into conventional strategies for the study of polymorphisms at microsatellite loci has allowed us to obtain information useful in determining genetic diversity and relationships among organisms. We have chosen, as a model for the testing of this strategy, several Solanum tuberosum varieties cultivated on Tenerife Island (Canary Archipelago) and a (TCT)(n) microsatellite located in intron I from the gene for granule-bound starch synthase. The data obtained confirm the high degree of agreement between molecular and farmer taxonomy.