This study aimed to investigate the callus induction and shoot regeneration to produce rootstock from stems and leaves explants of the Ohadi and UCB-1 pistachio cultivars. Plant growth regulators (PGRs), including combinations of BAP, Kin, IAA, NAA, and 2, 4-D, were added to Murashige and Skoog (MS) or Driver and Kuniyuki Walnut (DKW) media to induce callus induction and regeneration. Obtained calli were transferred to the DKW medium containing three different concentrations, 2 and 4 mg L−1 of BAP and 1 mg L−1 + 2 mg L−1 of BAP + NAA, to compare the frequency of shoot regeneration. The highest callus induction rate (96%) was observed in the DKW medium supplemented with 2 mg L−1 Kin + 0.5 mg L−1 NAA in the Ohadi stems. The highest callus induction frequency for leaves was obtained in the DKW medium supplemented with 2 mg L−1 BAP + 0.1 mg L−1 2, 4-D concentrations for both UCB-1 (73%) and Ohadi cultivar (71%). The highest shoot regeneration rate in Ohadi stems (41%) and leaves (20%) was observed in the medium supplemented with 2 mg L−1 NAA + 1 mg L−1 BAP. It resulted in significant differences (P ≤ 0.05) in callus induction and shoot regeneration between stems and leaves; stems generated more calli and shoots than leaves, and Ohadi significantly (P ≤ 0.05) inducted calli and generated shoots more than UCB-1. Altogether, these regeneration protocols, achieved from stems and leaves of the Ohadi and UCB-1 cultivars, may be helpful in future pistachio genetic transformation.

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