Table 1.
Mean values for plant growth and gas exchange parameters of four wheat genotypes (G) subjected to different water regimes (WR) and grown under low and high nitrogen
Data are the mean of 16 (WR) or 12 (G) replicates. Within each nitrogen treatment and within each water regime (40, 70. and 100% CC) or genotype (Mexa, Bicrecham-1, Lahn/Haucan. and Omrabi-3); values with different letters are significantly different according to the Tukey-b test (P <0.05).
| AB | SB | RWC | LDM | SLN | LN | SN | Tcum | Asat | E | gs | Ci/Ca | |
| Low N | ||||||||||||
| WR | ||||||||||||
| 40% | 7.9 c | 3.6 c | 85.1 b | 31.7 a | 1.1 b | 3.6 b | 1.8 a | 2.58 c | 16.2 b | 3.1 a | 0.32 a | 0.72 a |
| 70% | 11.6 b | 4.8 b | 90.5 a | 34.3 a | 1.4 a | 4.1 a | 1.9 a | 3.67 b | 18.6 a | 3.7 a | 0.37 a | 0.72 a |
| 100% | 32.2 a | 11.2 a | 91.3 a | 33.2 a | 1.4 a | 4.1 a | 1.9 a | 8.21 a | 17.4 a,b | 3.0 a | 0.30 a | 0.68 a |
| G | ||||||||||||
| Mexa | 14.9 b | 7.5 a | 87.7 a | 30.8 b | 1.0 c | 3.4 c | 1.9 a | 4.48 b | 15.4 b | 2.9 a | 0.30 a | 0.72 a |
| Bic-1 | 16.1 b | 6.4a | 87.9 a | 32.9 a.b | 1.3 b | 3.9 b | 1.9 a | 4.63 b | 16.9 b | 3.3 a | 0.34 a | 0.72 a |
| L/H | 17.2 b | 7.1 a | 89.8 a | 33.4 a,b | 1.3 b | 4.0 b | 1.9 a | 4.65 b | 16.4 b | 3.4 a | 0.30 a | 0.70 a |
| Omr-3 | 20.7 a | 5.2 b | 90.4 a | 35.2 a | 1.6 a | 4.5 a | 1.8 a | 5.51 a | 21.0 a | 3.5 a | 0.38 a | 0.69 a |
| High N | ||||||||||||
| WR | ||||||||||||
| 40% | 14.8 c | 5.6 c | 87.5 a | 32.1 a | 1.4 b | 4.3 a | 2.8 c | 3.25 c | 14.1 b | 2.1 b | 0.19 b | 0.62 a |
| 70% | 25.5 b | 8.7 b | 88.7 a | 34.7 a | 1.5 a,b | 4.4 a | 3.0 b | 5.56 b | 15.6 a,b | 2.3 b | 0.23 a,b | 0.64 a |
| 100% | 38.3 a | 11.8 a | 90.7 a | 34.9 a | 1.6 a | 4.5 a | 3.2 a | 7.85 a | 18.1 a | 2.9 a | 0.29 a | 0.66 a |
| G | ||||||||||||
| Mexa | 20.1 c | 10.0 a | 86.0 b | 31.1 b | 1.2 c | 4.0 c | 2.5 b | 5.03 b | 16.1 a | 2.8 a | 0.28 a | 0.69 a |
| Bic-1 | 26.9 b | 9.7 a | 91.2 a,b | 36.2 a | 1.6 a,b | 4.4 b | 3.2 a | 5.80 a,b | 15.8 a | 2.4 a | 0.24 a | 0.64 a |
| L/H | 24.5 b | 8.3 b | 88.5 a,b | 33.5 a,b | 1.4 b | 4.3 b | 3.0 a | 5.29 a,b | 15.4 a | 2.3 a | 0.22 a | 0.63 a |
| Omr-3 | 33.3 a | 6.9 c | 90.2 a | 34.7 a,b | 1.7 a | 4.9 a | 3.2 a | 6.10 a | 16.4 a | 2.2 a | 0.20 a | 0.58 b |
AB, aboveground biomass (g dry weight); SB, spike biomass (g dry weight); RWC, relative water content (%); SLN, specific leaf N (g m−2); LDM, leaf dry mass per unit leaf area (g m−2); LN, flag leaf nitrogen content (%); SN, shoot nitrogen content (%); Tcum, cumulative transpiration (L); Asat, light-saturated net CO2 assimilation rate (μmol CO2 m−2 s−1); gs, stomatal conductance (mol CO2 m−2 s−1); E, transpiration rate (mmol H2O m−2 s−1); Ci and Ca, intercellular and ambient CO2 concentrations.