Assessing the impact of copper oxide nanoparticles on growth attributes and regenerative potential in date palm (Phoenix dactylifera) micropropagation

Copper oxide nanoparticles (CuO-NPs; 0–40 mg L–1) were applied in MS medium to evaluate microbial contamination, shoot regeneration, and multiplication in date palm (Phoenix dactylifera L. cv. Barhee). Compared to the untreated control (0 mg L–1), copper oxide nanoparticles at 10 mg L–1 eliminated microbial contamination without phytotoxicity, yielding the highest regeneration frequency (88.60%) and maximum shoot number (14.25 shoots jar–1), whereas 40 mg L–1 caused 21.6% culture mortality. Supplementation with 10 mg L–1 CuO-NPs significantly increased shoot nutrient accumulation (N, P, K, Fe, Zn, Cu) relative to the control and other treatments (p ≤ 0.05). Antioxidant enzyme activities (SOD, CAT, POD), total soluble carbohydrates (152.10 mg g–1 DW), and free amino acids (8.05 mg g–1 DW) reached maximum values at 10 mg L–1, compared to the control, whereas soluble protein declined to 10.40 mg g–1 DW at 40 mg L–1, dropping below the untreated control. Root induction was highest at 10 mg L–1 CuO-NPs, while higher concentrations (≥ 20 mg L–1) suppressed rooting and induced root cellular modifications compared to the control. Plantlets derived from the 10 mg L–1 CuO-NPs treatment achieved the highest ex vitro acclimatization survival rate (88%). Genetic fidelity analysis using monomorphic RAPD and ISSR markers confirmed genetic stability among regenerated plantlets relative to mother plants and control cultures. DOI: https://doi.org/10.2478/foecol-2026-0023