محسن نصیری
معصوم ایزدپناه
شکوفه شهرزاد
طیبه سهیلانراقی
علیرضا میربادین

Wild service tree ( Sorbus tormhnalis) is an important forests species for wood production in Iran. This experiment was conducted for shoot proliferation in this species. Apical and lateral buds from elite trees were collected in northern forest (Loveh, Farim and Pardcola) in different seasons ( spring, autumn and winter).Sterilized explants were then cultured on basal MS medium. The results showed that the best treatments for explants sterilizing were: -1 % (w/v) Benomyl for 30 minutes - 70% Ethanol for 5 seconds -0.1 % Mercuric chloride with 1-2 drops of liquid soap for 1 minute The results indicated that the best season for taking explant from mother plants was late autumn. The suitable media for explants establishment and shoot proliferation were basal MS suplemented with 0.5 ppm BAP and 1I2N basal medium whit 1 ppm BAP, respectively. Using GA3 was not effective for stopping rosette growth and increasing internode length. This species is very hard to root , so that the rotine treatments didn,t cause any responses. But the rooting have been done with especial treatments such as: submersing the shoots in IDA solution(50ppm) for 24 hours, applying activated charcoal (3 gr per lit) and cultur.e on hormon free and decrased macro elements concentration(1I3) GD medum. Key words:,sorbus torminalis, wild service tree, micropropagation, . Organogenesis, In vitro culture