Table 1.
General Linear Model (GLM) results of a comparison of midday leaf water potential (Ψleaf), stomatal conductance (gST), photosynthetic rate (A) and water-use efficiency (A/gST) between C3 and C4 Panicoid species (represented as species nested in photosynthetic type) in response to conditions of adequate water supply, decreasing SWC and after re-watering
| Treatment | Treatment × date | Treatment × date × type | Treatment × date × species | |
|---|---|---|---|---|
| Plants subject to drought (Drought phase, days 0–48) | ||||
| Ψleaf | F1,239 = 505·0*** | F4,239 = 207·9*** | F6,239 = 5·4*** | F24,239 = 6·8*** |
| gST | F1,254 = 115·8*** | F6,254 = 46·0*** | F8,254 = 9·5*** | F32,254 = 5·5*** |
| A | F1,254 = 235·7*** | F6,254 = 108·6*** | F8,254 = 40·4*** | F32,254 = 3·9*** |
| A/gST | F1,254 = 1·0 n.s. | F6,254 = 34·6*** | F8,254 = 34·2*** | F32,254 = 5·0*** |
| Plants re-watered subsequent to drought (Re-watering phase, days 48–75) | ||||
| gST | F1,265 = 21·6*** | F8,265 = 34·9*** | F10,265 = 4·5*** | F40,265 = 5·2*** |
| A | F1,265 = 98·4*** | F8,265 = 84·1*** | F10,265 = 26·0*** | F40,265 = 4·2*** |
| A/gST | F1,265 = 20·7*** | F8,265 = 11·1*** | F10,265 = 19·7*** | F40,265 = 4·6*** |
All parameters were compared between well-watered controls and drought-treated plants and the analyses tested for the interacting effects of treatment, date, photosynthetic type and species. Separate analyses were conducted for the drought and re-watering phases of the experiment and levels of significance are indicated as: n.s. (not significant) P > 0·05; *P< 0·05; **P < 0·01; ***P < 0·001.