Abstract: The results indicated that the photosynthetic rate of hybrid wheat cv. Maiyou 4 was higher than its parents at different ecological factors. The saturated light intensity was about 1200 μE·m^-2·s^-1 for Maiyou 4 and ND 35, and about 1000 μE·m^-2·s^-1 for Yangmai 158. The photosynthetic rate of Maiyou 4 was 8.12% and 20.18% higher respectively than that of ND 35 and Yangmai 158 under saturated light intensity. The optimum temperature of photosynthesis in hybrid wheat and its parents were all about 25℃. But the former was more tolerant to high temperature. Under CO₂ concentration of 50-400 μL·L^-1, the photosynthetic rate of tested varieties all were linear increase with the inhance of CO₂ concentration, and the increase speed of Maiyou 4 in high CO₂ concentration (400-600 μL·L^-1) was faster than those of its parents. Under water stress conditions, compared with its parents, Maiyou 4 could sustain higher photosynthetic rate and its photosynthetic rate decreased slower in high osmotic potentials (-10-20 bar). In addition, Maiyou 4 could suit higher nitrogen levels than its parents. The study found that the responses of photosynthesis in Maiyou 4 more tended to female parent. The hybrid wheat having better ecological adaptability in photosynthesis than its parents probably related to its improved photosynthetic mechanism.

Key words: Hybrid wheat, Parents, Photosynthesis, Response