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In vitro multiplication of mature Eucalyptus grandis Trees

Eucalyptus grandis is a fast growing species with economic and industrial value. It is cultivated for its wood fibers which is widely used in the paper industry, domestic fuel and charchoal production. For clonal propagation of superior genotypes of the species, apical and axillary buds from adult elite trees in forests of northern Iran (Chamestan- vase research station) were collected in different seasons. Application of 0.1% mercuric chloride solution for 7 minutes was the best treatment for surface sterilization of the samples in summer. Different compositions of hormones were evaluated for regeneration. The best shoot multiplication was obtained using a modified MS medium containing half strength Nitrate containing BA, IBA, Kin and GA3 with concentration of 0.1, 0.01, 0.2 and 0.1 mgl"1, respectively. Shoots from the multiplication medium were transferred in MS medium (half strength Nitrate) containing 1 mgl" 1 Zeatin and 0.2 mgl"1 IAA for shoot elongation. Rooting of shoots were achieved in MS with V4 strength of macroelemants and 0.5 mgl"1 IBA plus 0.5 mgl"1 NAA. The plantlets were successfully established in greenhouse and field conditions.