Background: Wild apple, Malus sieversii, is an endangered species and a valuable genetic resource that requires a variety of conservation techniques. This study aimed to investigate the influence of different concentrations of hormones on wild apple regeneration from leaf and stem explants to establish an optimal regeneration system. Results:Leaves and stems derived from seedlings were cultured on several media supplemented with various concentrations of thidiazuron (TDZ) or 6-benzylaminopurine (BA) in different combinations with 1-naphthaleneacetic acid (NAA). The results showed that the most efficient shoot formation media (35% and 90%) were MS medium containing 4.0 mg L −1 TDZ and 1.0 mg L −1 NAA for leaf explants and MS medium containing 1.0 mg L −1 BA without NAA for stem explant. MS medium supplemented with 0.4 mg L −1 BA and 0.1 mg L −1 NAA (for shoot multiplication) and 1/2 MS + 0.1 mg L −1 NAA + 1.5% sucrose (for rooting) were effective media. Shoot regeneration from leaf explants was the most effective when the explants were placed abaxial side down onto the medium and were subjected to a pre-treatment of 3 weeks in darkness.Conclusions: An optimized regeneration system for M. sieversii that allowed regeneration within 2-3 months developed. The protocol developed herein can be used in large-scale clonal propagation for the conservation of wild apple, M. sieversii.

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