Il sorbo da legno : una risorsa da valorizzare

Sorbus. domestica (service tree) and S. torminalis (wild service tree) are characterised by slow growth and adaptability to low fertility soil. They are interesting for forestry, ornamental and food purposes and particularly important for timber production as the price of their good-quality wood is extremely high and its demand is increasing on the European market. Sorbus spp. are traditionally propagated by seed thus yelding a wide variability of the progeny. The use of in vitro culture as a tool of vegetative propagation could allow both the large-scale production of interesting genotypes and the exploitation of any carry over effects of the technique particularly in term of increased vigour of the ex in vitro plants. This research is part of a wider project founded by Regione Lombardia aimed at finding Sorbus torminalis and S. domestica distinctive individuals, collecting seeds and vegetative material to perform germination and micropropagation trials. Seedlings are growing in selection fields, monitored and selected for the best growth performances, form and stem characteristics. Those showing the desired traits undergo in vitro propagation with the goal to provide material to set up pilot fields, in areas with differing pedoclimatic conditions, for testing timber properties. A seedling orchard of S. torminalis was established in 2003 at the Experimental Farm of the Department of Crop Production, University of Milano. The objective of this orchard is the production of selected plus trees mainly based on trunk form traits and fast growth. Seedlings growth measures as recorded at pre-plantation and after two years in the field are reported. Some significant correlations between pre-plantation and post-plantation growth data are shown.