## 3 Results and Discussion
### Effect of Adaptation to Cd Stress on Biomass of the Middle European Ecotype of S. nigrum
\begin{table}
\begin{tabular}{l c c c c c c c c c c} \hline
**T** & **C\({}_{\text{soil}}\) mg kg\({}^{-1}\)** & **C\({}_{\text{n}}\) mg kg\({}^{-1}\)** & **EF\({}_{\text{n}}\)** & **TF** & **L\({}_{\text{n}}\) mg pot\({}^{-1}\)** & **LTF** \\  & **Symbol** & **N0** & **A50** & **N0** & **A50** & **N0** & **A50** & **N0** & **A50** & **N0** & **A50** \\ \hline \multicolumn{10}{c}{**Root**} \\
**0** & 0.22 \(\pm\) 0.08 & 0.57 \(\pm\) & 0.24 \(\pm\) & 2.59 \(\pm\) & 1.09 \(\pm\) & & & 1.20 \(\pm\) & 0.48 \(\pm\) & \\  & & 0.14 dA & 0.02 dB & 0.63 bA & 0.08 bB & & 0.49 cA & 0.06 bB & & \\  & & 50.83 \(\pm\) & 5.27 \(\pm\) & 4.83 \(\pm\) & & & 108.6 \(\pm\) & \\
**10** & 10.52 \(\pm\) 0.87 & 7.96 cA & 11.66 & 0.76 aA & 1.11 aA & & 21.9 bAc & bAc & \\  & & 112.72 \(\pm\) & 104.21 \(\pm\) & 6.22 \(\pm\) & 5.10 \(\pm\) & & 201.8 \(\pm\) & 150.1 \(\pm\) & \\
**20** & 20.44 \(\pm\) 1.96 & 11.95 bA & 21.42 bA & 0.56 aA & 1.04 aA & & 68.6 bA & 58.2 bAg & \\
**30** & 30.09 \(\pm\) 1.52 & 166.74 \(\pm\) & 110.16 \(\pm\) & 5.54 \(\pm\) & 3.66 \(\pm\) & & 210.4 \(\pm\) & 157.6 \(\pm\) & \\  & & 28.40 bA & 25.99 bB & 0.94 aA & 0.86 aB & & 124.5 bA & 92.6 bAB & \\
**50** & 50.49 \(\pm\) 2.29 & 324.07 \(\pm\) & 279.91 \(\pm\) & 6.42 \(\pm\) & 5.54 \(\pm\) & & 420.8 \(\pm\) & 401.7 \(\pm\) & \\  & & 31.20 aA & 49.01 aA & 0.62 aA & 0.97 aA & & & 17.5 aA & 142.1 aA & \\  & & & & & & & & & & \\
**0** & 0.22 \(\pm\) 0.08 & 0.82 \(\pm\) & 0.49 \(\pm\) & 3.72 \(\pm\) & 2.23 \(\pm\) & 1.40 \(\pm\) & 2.06 \(\pm\) & 10.9 \(\pm\) & 5.85 \(\pm\) & 8.77 \(\pm\) & 12.26 \(\pm\) \\  & & 0.34 dA & 0.08 dA & 1.53 bA & 0.34 cA & 0.23 bA & 0.27 aA & 5.92 cA & 0.81 bB & 1.63 bB & 0.86 aA \\
**10** & 10.52 \(\pm\) 0.87 & 81.05 \(\pm\) & 90.67 \(\pm\) & 7.70 \(\pm\) & 8.62 \(\pm\) & 1.48 \(\pm\) & 1.83 \(\pm\) & 957.9 \(\pm\) & 988.8 \(\pm\) & 8.91 \(\pm\) & 10.51 a \\
**20** & 20.44 \(\pm\) 1.96 & 111.05 \(\pm\) & 129.27 \(\pm\) & 5.43 \(\pm\) & 6.32 \(\pm\) & 0.88 \(\The values of enrichment and translocation factors justified high Cd-hyperaccumulative properties of the non-adapted Middle European ecotype of _S. nigrum_ (N0). Enrichment factor EF for roots ranged roughly from 2.6.to 6.4, and for shoots from 3.4 to 7.7, at translocation factor TF exceeding or close to 1, up to T20 (C\({}_{\rm soil}\) = 20.44 mg kg\({}^{-1}\) Cd). At higher Cd contents in the soil, TF was \(<\)1, but still high, while Cd concentrations in shoot were well above 100 mg kg\({}^{-1}\) Cd, thus meeting the requirements for a hyperaccumulator. The adapted variety (A50) under the same growing conditions displayed somewhat lesser range of EF for roots (from 1.1 to 5.5) and bigger for shoots (from 2.2 to 8.6), at TF \(>\) 1 up to T30 (C\({}_{\rm soil}\) = 30.09 mg kg\({}^{-1}\) Cd). All Cd concentrations in shoot of A50 at C\({}_{\rm soil}\) > 10 mg kg\({}^{-1}\) Cd were above 100 mg kg\({}^{-1}\) Cd, and bigger than in N0, thus confirming somewhat stronger Cd hyperaccumulative properties measured by its accumulation in shoot. Actual accumulated Cd loads in the investigated soil concentration range highlighted lesser Cd accumulation in the A50 root system than in that of N0 due to greater translocation of Cd loads from root to shoot (LTF). It showed a regular declining trend with the increase of Cd concentrations in the soil (LTF = 8.8 to 4.0 for N0 vs. LTF = 12.3 to 5.2 for A50). Remarkably, total Cd loads accumulated in roots and shoots of both N0 and A50 at increasing concentrations of Cd in the soil appeared to be similar to each other (Table 2). This means that the total amounts of Cd accumulated in the adapted A50 and non-adapted N0 varieties are basically similar, while long-range xylem sap transport from roots to leave vacuoles appeared to be more intense in the adapted variety A50. The pattern of Cd accumulation in root and shoot of both varieties of _S. nigrum_ as a hyperaccumulator clearly illustrates the difference in Cd uptake and translocation between Cd excluders and hyperaccumulators. Namely, in Cd excluders, such as e.g., _S.