In vitro propagation of three Iranian apricot cultivars

In vitro propagation is a useful method for clonal propagation of apricot; however, it is a highly genotype-dependent procedure. Eight different experiments were conducted to optimize and establish an efficient in vitro propagation protocol for three Iranian apricot cultivars, including Ordubad, Shams, and Qaysi. Sterilization, in vitro establishment, proliferation, root induction, and acclimatization steps were assessed. The fungal and bacterial infections were significantly decreased when nanosilver (2.5%) was applied in sterilization of initial explants. The highest number of active buds was obtained from summer-season collected lateral bud explants. The establishment responses of apricot cultivars to investigated basal culture media were different and the best results for Ordubad, Shams, and Qaysi cultivars were obtained from Driver and Kuniyuki (DKW), Woody Plant Medium (WPM), and modified Quoirin and Lepoivre (QL) basal media, respectively. The highest number of induced lateral shoots in Ordubad cultivar (2.33) was obtained from basal QL medium supplemented with BAP (4.44 μmol L⁻¹), GA₃ (1.44 μmol L⁻¹), and IBA (0.098 μmol L⁻¹). In Shams and Qaysi cultivars, the highest numbers of induced lateral shoots were obtained from WPM basal medium. The best combinations of BAP and GA₃ hormones to increase the number of induced lateral shoots in three Iranian apricot cultivars were 11.56 μmol L⁻¹ GA₃ and 4.44 μmol L⁻¹ BAP. In comparison with routine solid culture system, a 10 min h⁻¹ temporary immersion bioreactor system led to the significant increase of the number of induced lateral shoots, with higher shoot quality, in all investigated cultivars. The half strength QL medium supplemented with 19.68 μmol L⁻¹ of IBA resulted in the highest rooting percentage in all investigated apricot cultivars. The results of the present study would be applicable for cost-effective large-scale clonal propagation of other valuable cultivars of apricot.