Abstract

Eucalyptus globulus　Labill “Tasmanian Blue Gum” is the main species for pulp and paper production in the world due its exceptional fiber properties. There are 563,813 hectares planted in Chile that represents 23% of the total plantations with exotic species (INFOR, 2014). The species was introduced by the end of XIX century for coal mining poles in Colcura (BíoBío Region) and due to successive selection and propagation cycles a “Chilean Land Race” was formed that has been well adapted to dry climatic conditions in the country. By 1990 many organizations in Chile started breeding programs to improve frost hardiness, growth, yield and fiber quality of the species, but drought hardiness was not included as a trait. Last results of INFOR survey shows that the climatic change will decrease the productivity of plantations due to lower precipitation and extreme temperatures in the central and south region of Chile up to 6-8%. An INFOR research Project started on 2006 was oriented to select, recombine and propagate drought hardiness E. globulus genotypes in the semiarid region of Chile. Three populations were included for this purpose: (A) selected genotypes ranked by volume in a clonal seed orchard that correspond to the INFOR tree breeding program, (B) open pollinated families of 107 plus trees selected on extreme dry conditions (C) control pollinated families generated by intraspecific crosses of population B × A. This material combined the genetic superiority of the clonal orchard genotypes and the drought hardiness of the Chilean land race of E. globulus. This paper shows the results of two open-pollinated trials and one controlled pollination trial from these three populations planted in representative sites of dry land areas of the Bío-Bío Region on 2009-2010. Genetic parameters for drought tolerance E. globulus were obtained through the survival and growth of 24 control pollinated families and 61 open pollinated families at 5-6-year-old using as controls commercial seed sources of E. globulus and drought tolerant species like E. camaldulensis and E. cladocalyx. Conclusions are related with the applicability of this breeding strategies for improving drought tolerance of E. globulus in dry zones areas of the Bío-Bío Region including selection of best PC and OP progenies for commercial deployment.