EFFECT OF HIGH TEMPERATURES ON CHLOROPHYLL FLUORESCENCE OF DETACHED LEAVES OF RICE GROWING UNDER CO2 ENRICHMENT

Abstract:

When detached leaves of four rice cultivars, IR72, Guichao 2, Tesanai 2 and II You 4480, growing under 350 μl L^-1 (ambient) and 600 μl L^-1 (enrichment) CO₂ concentrations, were treated by different temperatures (30, 35, 40, 45, 50 ℃ ) for 30 min. Results showed that the cell membrane leakage increased with increasing temperature. There was a breakpoint with significant rise in 40-45 ℃ treatments in IR 72 and Guichao 2, whereas that in Tesanai 2 and II You 4480 were between 45-50 ℃. With increasing