A recent survey of Lycopersicon populations in the Galápagos Islands and a subsequent morphological characterization has permitted distinguishing four ecotypes of wild tomatoes. Three of them correspond to the previously described native forms L. cheesmanii f. cheesmanii, f. minor and Gal ppn., which are found in undisturbed environments. All of them have orange fruits and can be distinguished because f. cheesmanii and f. minor have very short internodes and somewhat succulent leaves, while Gal ppn. does not. Also, f. cheesmanii and f. minor are usually found in coastal areas, although f. minor is more abundant. Gal ppn. thrives in inner areas with a higher degree of soil humidity. On the other hand, f. minor is distinguished from f. cheesmanii, because the former has highly dissected leaves. The fourth ecotype corresponds to a previously unreported red-fruited type found in disturbed and wet soil areas in inhabited Santa Cruz Island and that is very similar in gross morphology to continental L. pimpinellifolium. Apart from these ecotypes, it is also possible to found cultivated L. esculentum var. esculentum and weedy L. esculentum var. cerasiforme. Preliminary data from AFLP analysis of wild Galápagos tomatoes, L. esculentum and continental wild L. pimpinellifolium show that L. cheesmanii can be unambiguously distinguished from L. esculentum and L. pimpinellifolium, and that all L. cheesmanii forms share a common genetic background. Despite similar morphology to L. pimpinellifolium the red-fruited wild tomatoes from Santa Cruz are genetically unrelated to L. pimpinellifolium or to L. cheesmanii and very close to L. esculentum var. cerasiforme and L. esculentum var. esculentum. All the evidences suggest that this red-fruited ecotype has appeared recently in the Galápagos Islands and that L. esculentum has had a main role in its origin.

Key words: AFLPs, Galápagos Islands, L cheesmanii, L. esculentum, L. pimpinellifolium, Lycopersicon