Table 1.
Analysis of variance of the effects of O3, drought, species, growth stage, and their interactions on photosynthetic gas exchange and A–Ci curve parameters of a primitive wheat, T. turgidum ssp. durum, and a modern wheat, T. aestivum L. cv. Xiaoyan 22
P-values were calculated using the general linear model with the main effects of O3, drought, species, growth stage, and their interactions. Two wheat species were well irrigated (88±6% SWC) and exposed to CF air (5±0ppb O3, 7 h d−1) or elevated O3 (83±7ppb O3 7 h d−1), or subjected to drought stress (42±4% SWC) and exposed to CF air or elevated O3 for 3 weeks during the post-flowering stage in open top chambers.
| Parameters | Ozone (O3) | Drought (ws) | Species (sp) | Stage (st) | O3×sp | ws×sp | O3×ws | O3×ws×sp | O3×ws×sp×st |
| Asat | 0.000 | 0.000 | 0.001 | 0.000 | 0.001 | 0.003 | 0.000 | 0.477 | 0.277 |
| gs | 0.012 | 0.000 | 0.019 | 0.000 | 0.045 | 0.412 | 0.026 | 0.375 | 0.776 |
| Ci | 0.000 | 0.000 | 0.777 | 0.000 | 0.006 | 0.000 | 0.624 | 0.554 | 0.000 |
| E | 0.009 | 0.000 | 0.044 | 0.000 | 0.057 | 0.714 | 0.172 | 0.572 | 0.822 |
| ITE | 0.003 | 0.004 | 0.534 | 0.000 | 0.411 | 0.017 | 0.200 | 0.393 | 0.837 |
| Vcmax | 0.000 | 0.010 | 0.000 | 0.000 | 0.001 | 0.093 | 0.004 | 0.874 | 0.244 |
| Jmax | 0.000 | 0.586 | 0.001 | 0.000 | 0.000 | 0.207 | 0.208 | 0.229 | 0.290 |
| R | 0.000 | 0.435 | 0.008 | 0.000 | 0.202 | 0.006 | 0.277 | 0.096 | 0.942 |
| CE | 0.000 | 0.089 | 0.019 | 0.000 | 0.009 | 0.144 | 0.005 | 0.108 | 0.433 |