Optimization strategy for establishing an efficient mature embryo reproduction system of Paeonia lactiflora Pall.

• Used Paeonia lactiflora seed embryos to find optimal stage medium. • Achieved high growth rates, built efficient mature embryo regeneration system. • Deeply explored roles and optimal concentrations of plant growth regulators. • Showed benefits of GA 3 alone or with 6-BA in embryo germination. • Found promoting effects of IBA, NAA, IAA on rooting with AC. Herbaceous peony ( Paeonia lactiflora Pall.) is one of the traditional famous flowers in China, which has high ornamental and medicinal value. In order to meet the needs of modern large-scale production of P. lactiflora and the development of new variety breeding work, we used P. lactiflora seed embryos as experimental materials to study the embryo germination of P. lactiflora , the induction, proliferation and rooting of multiple shoots, in order to establish an efficient and stable regeneration system of P. lactiflora . Our research outcomes demonstrated that the embryos could effectively germinate in Murashige and Skoog (MS) medium supplemented with gibberellin 3 (GA 3 ) and 6-benzyleaminopurine (6-BA), achieving a germination rate of up to 91.11 %. Direct seedling formation from P. lactiflora embryos was achievable in 1/2 MS medium enriched with 6-BA, 1-naphthaleneacetic acid (NAA), and GA 3 , with the highest seedling rate reaching 67.78 %. The induction of multiple shoots in P. lactiflora was facilitated by the use of Woody Plant Medium (WPM) containing 6-BA, GA 3 , and 30 g/L sucrose, resulting in an induction rate of 96.67 %. The proliferation of these shoots was further enhanced by incorporating gibberellin 3 (GA 3 ), 6-benzyleaminopurine (6-BA), and 30 g/L glucose into the WPM medium, resulting in a proliferation coefficient of 3.48. Effective rooting was achieved by adding indolebutyric acid (IBA) and activated carbon (AC) to the WPM medium, with a rooting rate of 73.33 %. In summary, our system improved the induction and rooting of multiple shoots of P. lactiflora by refining the basal medium, plant growth regulators, and carbon sources. This has led to the establishment of an efficient and stable regeneration system for P. lactiflora , providing a solid foundation for subsequent genetic transformation research.