Fig. 4

Effect of seed priming (30, 50, and 90 nm ZnO NPs at 0, 10, 50, 100, 500, and 1000 mg/L) on chlorophyll content of H. syriacus. Data are shown as mean ± standard deviation of three replications. Significant differences (p < 0.05) are indicated by column lines labelled with different letters according to Duncan’s test.