Wild pistachio (Pistacia atlantica subsp. kurdica) is one of tree species that cover much of the forest in northwest of Iran and used in industries, medicine and as food. The present study describes callus induction of the P. atlantica subsp. kurdica using seedling stem explants and the influence of different plant growth regulators including kinetin, benzyladenine (BA), thidiazuron (TDZ), 6- Benzylaminopurine (BAP) on the growth of calli. To determine the best concentration and composition of plant growth regulators to induce callus in wild pistachio, 13 treatments were compared in a completely randomized design with five replicates. Explants were excised from 7-10 days old in vitro grown seedlings and transferred to Woody Plant Medium (WPM) containing 3% sucrose and 0.7% agar supplemented different plant growth regulators. The data were collected for callus fresh weight, callus dry weight and callus induction percentage. GC-MS analysis of essential oil constituents of P. atlantica subsp. kurdica callus was performed. Results showed that concentrations and combination of various plant growth regulators had significant effect on callus induction and callus weight. The high efficient callus formation was observed in the medium containing different concentration of 6-BAP individually. The lowest and highest percentage of callus induction were in the treatment of BA 2 mg/l with NAA 1mg/1 (40%) and 6BAP 1mg/l (85%), respectively. GC-MS separated eight kinds of substances in callus. Main compositions of callus were Bornyl acetate (9.18%), Spathulenol (5.89%) and Ledol (5.37%).
