Establishment of a Tissue Culture System for Quercus palustris

Quercus palustris possesses significant ecological and ornamental value, yet its clonal propagation remains challenging, hindering germplasm utilization. To address this, an efficient tissue culture propagation system was established. This study systematically evaluated the effects of different plant growth regulator combinations on shoot proliferation, rooting, and callus induction using the Woody Plant Medium (WPM) as the basal culture. The optimal protocol among the tested cytokinin combinations (including 6-benzylaminopurine [6-BA] and kinetin [KT]) for shoot proliferation employed 0.3 mg/L 6-BA and 0.4 mg/L KT, achieving a mean proliferation coefficient of 5.22. For root induction, the most effective treatment consisted of 0.3 mg/L indole-3-butyric acid (IBA) and 0.2 mg/L naphthaleneacetic acid (NAA), yielding a rooting rate of 83.33%. Callus formation was optimally induced by 0.8 mg/L 6-BA combined with 0.3 mg/L NAA, resulting in a high induction rate of 90.63% along with a comparatively low browning incidence of 34.38%. Furthermore, the piperazine derivative fipexide (FPX) exhibited a dual role: promoting callus formation at 10 μmol/L while significantly inhibiting it at concentrations ≥ 20 μmol/L. The established system provides a robust technical foundation for the rapid propagation and germplasm conservation of Quercus palustris.