[EN] Prebred populations are a useful tool in breeding. Prebred populations have been developed derived from different wild tomato (Solanum lycopersium L.) relatives. BC3 populations are the most advanced available in the case of the wild relative S. peruvianum. The interest of accession S. peruvianum PI 126944 lies on its resistance to different pests and diseases. Advanced generations derived from an initial cross between PI 126944 and cultivated tomato are available at the ¿Instituto de Conservación y Mejora de la Agrodiversidad Valenciana¿ (COMAV). Concretely, the most advanced plant materials correspond to the third backcross to tomato of pseudo-F5 generations derived from the initial interspecific cross. On the other hand, CAPS (cleaved amplified polymorphic DNA) markers polymorphic between the parents of these generations have been identified. The objective of this work is the advance in the development of the set of introgression lines (ILs) of S. peruvianum PI 126944 in the tomato genetic background. With this aim, on one hand, seeds from selfing of the plant materials available will be obtained. On the other hand, new data will be produced regarding the genotype of the generations available. The work will be carried out with a set of pants belonging to advanced generations derived from PI 126944. Plant materials conserved in vitro will be acclimatized and transferred to a greenhouse, to check if they bloom, set fruits from selfing and if these fruits have viable seeds. To continue with the genotyping, DNA isolation will be carried out from young leaves tissue, using the CTAB method. Initially, the genotyping will be done with CAPS markers. After PCR amplification, results will be visualized by agarose gel and ethidium bromide staining. Alternatively, a genotyping by sequencing (GBS) analysis is in progress, with the objective of identifying SNP markers (single nucleotide polymorphism) between the initial parents of the ILs. Provided the results from this GBS analysis are available in the course of this TFG, the data will be used in the development of new markers useful in the genotyping of these plant materials. TFGM