Table 3.
Mean values and corresponding ANOVA results for anatomical (perZ1: outer zone area (Z1) in % of internode section area, perSclZ1: percentage of sclerenchyma tissue (red stained) in % of Z1 area, densVBZ2: density of vascular bundles in central zone (Z2) in number of vascular bundles per mm2 and perBluZ2: percentage of blue tissue in % of Z2 area) and biochemical (ADL: Acid Detergent Lignin in %DW, Cell_VS: cellulose content in %DW, Hemi_VS: hemicellulose content in %DW, SS: soluble sugars in mg.g-1DW and AcBL: lignin content by acetyl bromide method in mg.g-1DW).
| Mean | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 2013 | 2014 | ANOVA | ||||||||
| Trait | Date | WW | WD | WW | WD | Y | G | T | GxY | GxT |
| perZ1 (% of section area) | End stress | 16.93 | 18.22 | 15.48 | 11.21 | 0.621 | 0.026 | 0.085 | 0.026 | 0.138 |
| Harvest | 18.40 | 18.32 | 17.40 | 18.03 | 0.276 | 0.034 | 0.871 | 0.005 | 0.341 | |
| perSclZ1 (% of Z1 area) | End stress | 49.98 | 39.85 | 21.03 | 18.82 | 0.000 | 0.176 | 0.213 | 0.013 | 0.998 |
| Harvest | 61.42 | 57.91 | 50.29 | 42.99 | 0.672 | 0.700 | 0.484 | 0.014 | 0.289 | |
| densVBZ2 (nb/mm2) | End stress | 1.10 | 1.07 | 1.19 | 1.60 | 0.614 | 0.676 | 0.033 | 0.606 | 0.767 |
| Harvest | 1.11 | 1.15 | 1.12 | 1.25 | 0.807 | 0.210 | 0.517 | 0.475 | 0.764 | |
| perBluZ2 (% of Z2 area) | End stress | 10.07 | 29.20 | 58.32 | 79.86 | 0.000 | 0.847 | 0.085 | 0.124 | 0.823 |
| Harvest | 2.82 | 6.91 | 5.53 | 12.22 | 0.931 | 0.091 | 0.249 | 0.264 | 0.875 | |
| ADL (%DW) | End stress | 4.84 | 3.81 | 3.89 | 1.79 | 0.012 | 0.651 | 0.000 | 0.964 | 0.599 |
| Harvest | 5.54 | 5.71 | 5.11 | 4.67 | 0.365 | 0.013 | 0.882 | 0.372 | 0.447 | |
| Cell_VS (%DW) | End stress | 39.47 | 34.62 | 39.21 | 27.60 | 0.386 | 0.899 | 0.000 | 0.550 | 0.554 |
| Harvest | 36.17 | 37.52 | 35.92 | 33.94 | 0.624 | 0.000 | 0.581 | 0.234 | 0.828 | |
| Hemi_VS (%DW) | End stress | 26.96 | 25.52 | 24.85 | 24.29 | 0.085 | 0.026 | 0.083 | 0.000 | 0.839 |
| Harvest | 25.69 | 25.81 | 25.26 | 24.81 | 0.512 | 0.001 | 0.909 | 0.029 | 0.763 | |
| SS (mg.g-1 DW) | End stress | 143.21 | 219.75 | 265.94 | 286.95 | 0.003 | 0.915 | 0.167 | 0.343 | 0.168 |
| Harvest | 236.62 | 258.82 | 252.86 | 269.94 | 0.651 | 0.008 | 0.363 | 0.071 | 0.268 | |
| AcBL (mg.g-1 DW) | End stress | 109.83 | 95.40 | 53.88 | 56.46 | 0.000 | 0.812 | 0.432 | 0.670 | 0.633 |
| Harvest | 130.33 | 129.49 | 137.34 | 125.92 | 0.357 | 0.199 | 0.521 | 0.498 | 0.373 | |
Variables are measured at two stages (end of the water deficit period (end stress) and final harvest), at two internode levels on the main stem of two hybrids G (G1: Biomass140, G4: RE1xAR4), on 2 years in the field (2013, 2014) under two water treatments T (well-watered: WW, 1 month water deficit during stem elongation: WD). Each value in the table is the average of 24 internodes at rank 2 (end stress) and 4 (harvest) below the last ligulated leaf phytomer (p-values < 0.05 are indicated in bold).