Fig 5. Effects of exogenous H₂O₂ on adventitious root formation of apple stem cuttings.

(A) Adventitious root formation in apple stem cuttings after 18 days in rooting medium or rooting medium supplemented with H₂O₂ (1 mM, 5 mM, and 25 mM). “+” represents presence, “−” represents absence. The concentrations of IBA and NAA were 0.5 mg L⁻¹ and 0.1 mg L⁻¹, respectively. (B) Percent rooting. Bars indicate mean and SE from three biological replicates; n = 6 individuals per replicate. Asterisks indicate significant differences between stem cuttings subcultured in 1/2 MS and stem cuttings subcultured in 1/2 MS + IBA +NAA (Student’s t-test, **P < 0.01, *P < 0.05). (C) Adventitious root number per cutting. Adventitious root number per cutting was counted at 18 days. Bars indicate mean and SE from three biological replicates; n = 6 individuals per replicate. The statistical analysis was conducted using Duncan’s multiple range test (P < 0.05). The different lowercase letters indicate significant differences.