Elm breeding for DED resistance, the Italian clones and their wood properties

In Italy, an elm breeding programme to develop Dutch elm disease (caused by Ophiostoma ulmi)-resistant trees has been established by crossbreeding Asian elms with indigenous species, in order to produce individuals that combine resistance of the first with growth characteristics and higher degree of environmental adaptability of the second. Thus, the favourable adaptation of Ulmus pumila in Italy has been explored: San Zanobi and Plinio are two recent results of this research and many others promising clones as FL090, FL146, FL441, FL568, FL634, are in the final stage of field testing. The resistance levels of all these clones were significantly higher level of resistance than Lobel and Urban in several assessments during different years. First technological tests indicate that the wood characteristics of San Zanobi and FL090 clones are comparable to those of elm wood traditionally present on the market, thus highlighting that those clones is likely to satisfy the elm wood demand. The present characterization needs to be confirmed by further evaluations of mature trees having bigger diameters and allowing industrial trials, still not available so far.