Effects Of Short-term High Temperature Stress On Photosynthetic Characteristic In High Yield Winter Wheat

Effects of high temperature on photosynthetic rate, characteristic of chlorophyll a fluorescence, potosystemⅡ(PSⅡ) functions and subsequent recovery were investigated in high yield winter wheat cultivar 01-35 and Lumai14(L14) by measurement of chlorophyll fluorescence, gas exchange and oxygen evolution. Our aim was to explore the mechanism of heat-tolerance in 01-35. The main results are as follows:1. Photosynthetic rate in 01-35 and L14 decreased obviously when they suffered short-term high temperature stress. At anthesis and maturity stage, there were no significant differences in both of them. However, photosynthetic rate in 01-35 was obvious higher than that in L14 at grain filling stage. Moreover, photosynthetic rate in 01-35 at grain filling stage was higher than that at blooming stage when stress temperature was below 40℃, which indicated that high temperature tolerance of photosynthetic apparatus in 01-35 was higher than that in L14 at grain filling stage.2. Fv/Fm, Fv′/Fm′andΦPSⅡin 01-35 and L14 decreased considerably under short-term high temperature stress. No significant difference was observed in both of them at anthesis. But Fv/Fm, Fv′/Fm′andΦPSⅡin...