Table 1 Broad sense pedigree heritability estimates for adventitious root-related phenotypes measured
|  | Phenotypic values | Mean ± SD |  |  |
|---|---|---|---|---|
Trait | P. trichocarpa × P. deltoides | P. deltoides | Progeny Variation (Mean ± SD) | Broad sense heritability H 2 ± SD |
Root architectural traits | ||||
 Total root length (cm) | 56.5 ± 6.2 | 86.4 ± 9.0 | 123.1 ± 94 | 0.153 ± 0.051 |
 Total root surface area (cm2) | 10.0 ± 1.1 | 23.4 ± 2.4 | 25.1 ± 19 | 0.169 ± 0.052 |
 Total root volume (cm3) | 0.14 ± 0.1 | 0.51 ± 0.1 | 0.42 ± 0.3 | 0.185 ± 0.053 |
 Average diameter (mm) | 0.56 ± 0.2 | 0.93 ± 0.1 | 0.70 ± 0.2 | 0.236 ± 0.055 |
 Length of root branches (cm) | 25.6 ± 10.2 | 28.5 ± 8.6 | 55.7 ± 49 | 0.115 ± 0.049 |
 Surface area of root branches (cm2) | 2.90 ± 0.3 | 2.40 ± 0.1 | 4.33 ± 3.8 | 0.117 ± 0.049 |
 Volume of root branches (cm3) | 0.28 ± 0.8 | 0.20 ± 0.6 | 0.034 ± 0.03 | 0.120 ± 0.049 |
 Total length of primary roots (cm) | 30.8 ± 9.1 | 57.6 ± 8.2 | 67.1 ± 50 | 0.193 ± 0.053 |
 Surface area of primary roots (cm2) | 6.90 ± 1.5 | 20.1 ± 2.5 | 19.4 ± 15 | 0.187 ± 0.053 |
 Volume of primary roots (cm3) | 0.19 ± 0.1 | 0.61 ± 0.1 | 0.49 ± 0.4 | 0.177 ± 0.053 |
Number of adventitious roots (day 18) | 7.36 ± 0.8 | 4.92 ± 0.5 | 5.92 ± 4.0 | 0.341 ± 0.056 |
Root biomass (mg) | 4.73 ± 0.9 | 27.5 ± 3.2 | 19.3 ± 20 | 0.144 ± 0.051 |