Photosynthetic response of Eragrostis tef to temperature

摘要: Photosynthetic characteristics of leaves tef, Eragrostis tef (Zucc.) Trotter, plants, grown at 25/15°C (day/night), were measured temperatures from 18 to 48°C. The highest carbon exchange rates (CER) occurred between 36 and 42°C. averaged 27 μmol m−2 s−1. At lower or higher temperatures, CER was reduced, but the availability CO2 mesophyll, as internal concentration, when above below optimum for CER. In addition, stomatal conductance not correlated, residual highly correlated with (r = 0.98). additional experiments, relative 13C composition leaf tissue 25, 35 45°C -14.4 per mille, confirming that is a C4 grass species. Dry matter accumulation than lowest 45°C. Leaf increased hyperbolically light 0 2000 s−1 PPFD. CER, 31.8 μ-mol m-2 s−1, 35°C PPFR. high light, 25 nearly equal because 25°C. Residual was, however, clearly compared treatments. Stomatal in either set yet always 42°C across suggesting photosynthetic potential temperature range.