Table 2.
Shoot zinc (Zn) accumulation in nongrafted and grafted plants of the Zn hyperaccumulator Thlaspi caerulescenes (Tc) and the related nonaccumulator Thlaspi perfoliatum (Tp). Plants were treated with increasing concentrations of Zn(NO3)2 (0, 0.5, 1, 2, 4, 8 and 16 mm) for 7 wk
| Zn applied to the soil (mm) |
||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Shoot/root | 0.0 | 0.5 | 1.0 | 2.0 | 4.0 | 8.0 | 16.0 | |||||||
| Tc | 812 | a | 904 | a | 2030 | a | 3143 | a | 2914 | a | 8 890 | a | 10 856 | a |
| Tc/Tc | 637 | a | 873 | a | 1947 | a | 3006 | a | 3411 | a | 10 193 | a | 10 551 | a |
| Tc/Tp | 82 | b | 142 | b | 623 | b | 1022 | b | 1306 | b | 2 770 | c | 3 489 | c |
| Tp | 110 | b | 174 | b | 218 | c | 354 | b | 446 | b | 1 760 | c | 1 824 | c |
| Tp/Tp | 106 | b | 146 | b | 264 | c | 575 | b | 1199 | b | 2 595 | c | 2 883 | c |
| Tp/Tc | 643 | a | 792 | a | 1027 | b | 2698 | a | 4274 | a | 5 889 | b | 8 161 | b |
Plants are ungrafted T. caerulescens (Tc) and T. perfoliatum (Tp), self-grafted T. caerulescens (Tc/Tc) and T. perfoliatum (Tp/Tp), and plants with a T. caerulescens shoot scion with a T. perfoliatum rootstock (Tc/Tp) and a T. perfoliatum shoot scion with a T. caerulescens rootstock (Tp/Tc). Different letters denote significant differences between means for grafted and nongrafted plants under the same treatment (ANOVA test, P ≤ 0.05). Samples sizes for the experiment were Tc (n = 8), Tc/Tc (n = 6), Tc/Tp (n = 5), Tp (n = 7), Tp/Tp (n = 7) and Tp/Tc (n = 7).