Table I.
Photosynthesis and dark respiration of aspen leaf discs
| Leaf Stage | Initial Respirationa | Post-Photosynthesis Respirationb | Maximum Photosynthesisc |
|---|---|---|---|
| μm O2 m−2 s−1 | |||
| YL | 2.2 ± 0.28 | 4.6 ± 0.50 | 2.4 ± 0.35 |
| EL | 1.6 ± 0.24 | 3.6 ± 0.42 | 4.1 ± 0.16 |
| ML | 0.8 ± 0.07 | 3.7 ± 0.58 | 5.9 ± 0.49 |
Photosynthetic O2 evolution and respiratory (dark) O2 consumption by low-light-adapted discs before and immediately following photosynthesis of YL, EL, and ML discs. Values represent the mean ± se (n = 6).
a
Dark respiration measured for a period of 10 min using discs from 2-h low-light-adapted plants.
b
Dark respiration measured for a period of 10 min immediately following a 30-min period of photosynthesis.
c
Maximum rate of photosynthesis during a 30-min period following the addition of 8 mm sodium bicarbonate.