Excelling the progenitors: Breeding for resistance to Dutch elm disease from moderately resistant and susceptible native stock

Under the continuous pressure of Dutch elm disease (DED) in Europe, increasing genetic diversity Ulmus minor trees resistant to Ophiostoma novo-ulmi is a priority for species conservation and reintroduction. In this work we screened 121 U. genotypes resistance O. under field experimental conditions. The had been previously obtained through controlled crosses between two moderately (dams) one susceptible (sire) genotypes. After years artificial inoculations with novo-ulmi, transgressive was present but not prevalent, moderate relation found tree growth susceptibility. Heritability estimates DED endorse significant control higher blocks milder symptoms. Three excelled their high resistance, showing average foliage wilting values below 30% after inoculations. fingerprint, leaf phenology morphology, ornamental traits these three were evaluated facilitate identification use by stakeholders. Nuclear microsatellite profiling displayed unique barcodes each genotype, ensuring traceability plant material. Morphological phenological are quite similar fall within standards. base results, new native proposed as basic materials reintroduction Western Europe.