FB-MRS is an apple gene providing resistance to fire blight

To date the use of natural resistance to manage fire blight epidemics in apple orchards has been limited by the reduced availability of such traits in commercial varieties as well as the very poor fruit quality of resistant wild apple genotypes. Such natural resistance offers great environmental advantages compared to any other disease control methods i.e. less treatments with chemicals and less tractor rides. We undertook the positional cloning of the fire blight resistance gene located on the linkage group 3 of Malus ×robusta 5 (Mr5), a wild apple genotype immune to European strains of Erwinia amylovora. A single candidate gene (FB_MR5) was identified and validated by a transgenic approach, transforming the fire blight susceptible cultivar ‘Gala’. This represents an unprecedented opportunity to deploy Malus-own resistance by cisgenics, similarly to what we recently reported for the scab resistance gene Rvi6, showing that such GM product may represent an effective and sustainable approach in fire blight management. Current state of the research will be presented.