Farmers around the world are facing too many problems cultivating plants, especially plant diseases. Erwinia amylovora is a bacteria known as Fire Blight disease that can destroy orchards in one single season. Growers and scientists alike would agree that Fire Blight is not like other plant diseases. The economic impact is very high, which is the main reason why this disease has the attention of everyone who cultivates apple or pear fruits. Plant diseases are kept under control in general by two main measures; first, by applying pesticides, and second, by cultivating plant varieties that are genetically resistant to those diseases or by creating resistant cultivars (plant breeding), which practically is the field where we are focused on. During this research project are done a lot of crossings, artificial inoculation with different bacterial strains, a large number of PCR tests through different protocols focused in plant and bacteria (Erwinia amylovora) DNA. Genetic map is the last step of the project to determine Gens that contribute on the resistance of the plants to E.a.