Table 3.
Biomass production (ton DW ha-1 year-1), Cd and Zn extraction potential (g ha-1 year-1) of the three most promising tobacco clones, sunflower mutants, and experimental and commercial SRCs Tobacco and sunflower data were averaged over 2 years.
| Block | Type | Biomass production (stem for SRC) (ton DW ha-1 y-1) | Cd extract. potential (g ha-1 year-1) | Zn extract. potential (kg ha-1 year-1) | |||
|---|---|---|---|---|---|---|---|
| Species (#plants/ha) | Mutants, clones (# SRC clones) | Range (min max) | Mean (SD) | Range (min max) | Mean (SD) | Range (min max) | Mean (SD) |
| Tobacco I (15 625) | NBCu108 | 4.3–5.2 | 4.8 (0.2) | 67.8–143.8 | 105 (30) | 1.9–2.6 | 1.9 (0.5) |
| FOP | 3.07–5.0 | 4.9 (0.2) | 66.1–194.8 | 95.2 (31) | 1.2–2.7 | 1.7 (0.5) | |
| NFCu719 | 3.9–5.3 | 5.1 (0.7) | 79.2–111.4 | 93.1 (10) | 1.1–2.5 | 1.5 (0.3) | |
| Sunflower I (27 778) | 15-35-190-04 | 5.6–7.1 | 6.3 (2.3) | 31.5–76.2 | 42.5 (21) | 1.9–7.5 | 5.6 (3.2) |
| 14-185-04 | 5.7–10.1 | 8.6 (0.1) | 26.5–80.3 | 35.6 (30) | 1.7–6.7 | 4.2 (2.1) | |
| 86-35-190-04 | 3.7–7.2 | 5.4 (2.4) | 18.1–41.5 | 30.2 (2) | 2.1–4.6 | 3.5 (2.1) | |
| Poplar I (10 000) | {D(T × M)} (1) | – | 9.9 | – | 87.2 | – | 2.3 |
| {T} (2) | 6.2–6.4 | 6.3 (0.2) | 61.5–105.1 | 83.3 (30) | 2.5–2.7 | 2.6 (0.2) | |
| {T × T} (8) | 6.1–14.7 | 8.5 (3.0) | 35.5–125.9 | 67.4 (31) | 1.3–4.4 | 1.5 (1.2) | |
| Willow I (10 000) | {v} (9) | 3.6–7.8 | 5.7 (1.4) | 83.3–152.0 | 115 (28) | 2.9–4.1 | 3.1 (0.9) |
| {v × v} (1) | – | 3.0 | – | 54.0 | – | 2.4 | |
| {a × a} (14) | 3.6–15.6 | 7.1 (3.5) | 30.0–109 | 41.9 (23) | 0.8–3.4 | 2.0 (1.2) | |
| Poplar II (15 000) | {T × M} (1) | – | 5.1 | – | 99.0 | – | 1.5 |
| {T} (3) | 4.5–9.2 | 6.5 (2.4) | 65.0–142.1 | 95.1 (41) | 1.7–3.3 | 2.7 (0.3) | |
| {T × T} (15) | 2.6–7.5 | 4.6 (1.6) | 43.3–102.6 | 69.2 (22) | 1.1–2.9 | 1.7 (0.4) | |
| Willow II (15 000) | {v × v} (5) | 2.7–5.0 | 4.2 (0.9) | 62–110 | 91.7 (18) | 1.6–3.2 | 2.6 (0.6) |
| {a × a} (7) | 3.2–7.0 | 4.5 (1.4) | 16.1–56.7 | 29.9 (13) | 1.1–3.2 | 1.1 (0.3) | |
| Poplar III (10 000) | Vesten (D × N) | – | 6.2 (0.7) | – | 143.5 (9) | – | 2.2 (0.2) |
| Koster (D × N) | – | 5.2 (1.4) | – | 90.1 (41) | – | 1.5 (0.6) | |
| GrimmingeD (T × D) | – | 5.1 (0.1) | – | 77.0 (7.1) | – | 1.3 (0.1) | |
| Willow III (15 000) | Z. Driebast (Tr) | – | 12.3 (3) | – | 185 (49) | 5.1 (0.5) | |
| Loden (Da) | – | 3.2 (0.7) | – | 119 (18) | 3.2 (0.8) | ||
| Tora (S × V) | – | 3.3 (0.4) | – | 71.2 (14) | 1.6 (0.2) | ||
D, Populus deltoides; M, Populus maximowiczii; N, Populus nigra; T, Populus trichocarpa; A, Salix alba; Da, Salix dasyclados; F, Salix fragilis; S, Salix schwerinii; Tr, Salix triandra; V, Salix viminalis; {}, collection of all experimental clones with this crossing type (# clones). Values are min-max and mean ± SD. “-” means data not available. Stem biomass production and Cd and Zn concentrations in the stems of commercial poplar clones were derived from Van Slycken et al. (2015), those of commercial willow clones from Van Slycken et al. (2013b). Extraction potentials of these commercial clones were calculated based on the abstracted data.
SRC data were collected from the first four growing seasons of most promising experimental clones and commercial clones planted on the field in 2006. The data from the commercial poplar clones were abstracted from Van Slycken et al. (2015), and the data from the commercial willow clones from Van Slycken et al. (2013b). The values in bold indicate the most promising clone within its genus.