Euphytica (2008) 163:45–56 DOI 10.1007/s10681-007-9573-5 123 Breeding against Dutch elm disease adapted to the Mediterranean climate Alberto Santini · Nicola La Porta · Luisa Ghelardini · Lorenzo Mittempergher Received: 29 June 2007 / Accepted: 10 September 2007 / Published online: 20 September 2007  Springer Science+Business Media B.V. 2007 Abstract Breeding for resistance was considered one of the possible ways to limit the damages caused by the epidemics of Dutch elm disease (DED) during the last century. The elm breeding program developed by CNR in Italy was based on the idea that the Medi- terranean environment would need its own speciWc selections. A base broadening of the genetic resources was operated. A base of native elms with a set of good characters to act as parents was bred with diVerent Asian elm species that showed the ability of acclima- tization to the diVerent climates in which elms have to be planted. For this aim a large collection of elm species was constituted, followed by hybridisation studies. Progenies were tested for DED resistance. The more resistant clones were planted in trial Welds characterised by contrasting Mediterranean climates in order to select the best potential genotypes adapted either to coastal or to mountain environmental conditions. More than 60 clones resistant, fast-grow- ing and showing remarkable aesthetic ornamental characters were obtained. Keywords Dutch elm disease · Breeding · Resistance · Elm · Mediterranean climate Introduction Starting from around 1910 in Northwest Europe two destructive pandemics of Dutch Elm Disease (DED) caused by the introduction of two very diVerent fun- gal pathogens, Ophiostoma ulmi (Buisman) and O. novo-ulmi (Brasier) aZicted the elms in Europe and, 20 years later, in North America (Brasier 2000; Guries 2001). The gravity and impressiveness of the damages caused by the disease stirred up the interest of public opinion and researchers to explore solutions to the problem (Rohring 1996). The idea of searching for resistance to DED in the European elm species and elm populations, associ- ated with the hope of enhancing resistance through breeding, arose in 1928 at the Willie Commelin Scholten Phytopathological Laboratorium in Baarn (The Netherlands), (Heybroek 1993, 2000), where a wide collection of elms was constituted and the Wrst resistant cultivars were obtained within the Euro- pean species. Following the Dutch example, several elm breed- ing programmes in Europe were set up in several A. Santini (&) · L. Ghelardini · L. Mittempergher Istituto per la Protezione delle Piante – C.N.R, Via Madonna del Piano, 10 50019 Sesto Worentino, Italy e-mail: a.santini@ipp.cnr.it L. Ghelardini e-mail: l.ghelardini@ipp.cnr.it L. Mittempergher e-mail: loremitte@libero.it N. La Porta IASMA Research Center Department of Natural Resources, Via E. Mach 2, 38010 S. Michele a/A, TN Italy e-mail: nicola.laporta@iasma.it