## 3 Results
### Effect of ZnONPs on In Vitro Blackberry Growth
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Biometric Feature**} & \multirow{2}{*}{**Number of Months**} & \multicolumn{6}{c}{**Concentration of ZnO-NPs [mg dm\({}^{-3}\)]**} \\ \cline{3-8}  & & **0** & & & & \\  & & **(Control)** & **10** & **20** & **30** & **40** & **LSD\({}_{\mathbf{p}}\) = 0.05** \\ \hline \multirow{2}{*}{Number of shoots} & 2 & 4.67 \({}^{\text{a}}\) & 4.75 \({}^{\text{a}}\) & 4.46 \({}^{\text{a}}\) & 4.18 \({}^{\text{a}}\) & 2.93 \({}^{\text{b}}\) & 1.645 \\  & 3 & 6.08 \({}^{\text{a}}\) & 6.10 \({}^{\text{a}}\) & 5.54 \({}^{\text{a}}\) & 5.11 \({}^{\text{a}}\) & 3.92 \({}^{\text{b}}\) & 2.056 \\ \hline \multirow{2}{*}{Shoot length [cm]} & 2 & 2.14 \({}^{\text{a}}\) & 1.91 \({}^{\text{a}}\) & 1.78 \({}^{\text{a}}\) & 1.38 \({}^{\text{b}}\) & 0.98 \({}^{\text{b}}\) & 0.679 \\  & 3 & 2.52 \({}^{\text{a}}\) & 2.34 \({}^{\text{a}}\) & 2.21 \({}^{\text{a}}\) & 1.94 \({}^{\text{b}}\) & 1.85 \({}^{\text{b}}\) & 0.454 \\ \hline \multirow{2}{*}{Number of roots} & 2 & 0.85 \({}^{\text{a}}\) & 0.74 \({}^{\text{a}}\) & 0.63 \({}^{\text{a}}\) & 0.52 \({}^{\text{a}}\) & 0.00 \({}^{\text{a}}\) & ns \\  & 3 & 3.77 \({}^{\text{a}}\) & 2.82 \({}^{\text{a}}\) & 2.61 \({}^{\text{a}}\) & 1.72 \({}^{\text{b}}\) & 0.92 \({}^{\text{b}}\) & 2.701 \\ \hline \multirow{2}{*}{Root length [cm]} & 2 & 0.15 \({}^{\text{a}}\) & 0.11 \({}^{\text{a}}\) & 0.10 \({}^{\text{a}}\) & 0.09 \({}^{\text{a}}\) & 0.00 \({}^{\text{a}}\) & ns \\  & 3 & 1.67 \({}^{\text{a}}\) & 0.55 \({}^{\text{b}}\) & 0.54 \({}^{\text{b}}\) & 0.53 \({}^{\text{b}}\) & 0.26 \({}^{\text{b}}\) & 0.506 \\ \hline \multirow{2}{*}{Fresh weight of plant [g]} & 2 & 0.41 \({}^{\text{a}}\) & 0.34 \({}^{\text{a}}\) & 0.26 \({}^{\text{a}}\) & 0.24 \({}^{\text{b}}\) & 0.14 \({}^{\text{b}}\) & 0.172 \\  & 3 & 0.59 \({}^{\text{a}}\) & 0.38 \({}^{\text{a}}\) & 0.35 \({}^{\text{a}}\) & 0.31 \({}^{\text{b}}\) & 0.20 \({}^{\text{b}}\) & 0.241 \\ \hline \multirow{2}{*}{Increase in fresh weight of plant [g]} & 2 & 0.36 \({}^{\text{a}}\) & 0.29 \({}^{\text{a}}\) & 0.20 \({}^{\text{a}}\) & 0.19 \({}^{\text{a}}\) & 0.09 \({}^{\text{b}}\) & 0.165 \\  & 3 & 0.54 \({}^{\text{a}}\) & 0.33 \({}^{\text{a}}\) & 0.30 \({}^{\text{a}}\) & 0.26 \({}^{\text{b}}\) & 0.15 \({}^{\text{b}}\) & 0.145 \\ \hline \hline \end{tabular}  
Different letters indicate significant differences at \(p\) = 0.05, ns—no significant differences.  
\end{table} 
Table 1: Influence of increased content of ZnO-NPs in MS solid medium on biometric features of blackberry (_Rubus fruticos_ L.), Navaho variety (mean value of feature/explant). After two and three months of in vitro culture, the average fresh weight of Navaho blackberry plantlets (0.41 and 0.59 g) and the increase in fresh weight (0.36 and 0.54 g) were highest in the control. The smaller number of roots and shorter shoot length and root length in the samples growing on media with zinc oxide nanoparticles reduced the weight of the plantlets. After both two and three months of culture, the fresh weight and increase in fresh weight were statistically significantly reduced in the treatments with 30 and 40 mg dm\({}^{-3}\) ZnONPs, by twofold and threefold, respectively, compared to the control (Table 1). The biological quality of the blackberry plantlets from the in vitro culture was evaluated by determining the content of selected minerals; secondary metabolites, i.e., phenolic compounds; antioxidants; and photosynthetic pigments.