Abstract: With wheat and pea seedlings as test materials, this paper studied the effects of UV-C radiation on their leaf photosynthetic characteristics and antioxidant enzyme activities. The results showed that enhanced UV-C radiation could markedly decrease the photosynthetic rate (P_n), stom-atal conductance (G_s), intercellular CO₂ concentration (C_i), transpiration rate (T_r) and carboxylation efficiency (C_E) of pea leaves, but for wheat leaves, these parameters were increased first and decreased then. Under UV-C condition, the CO₂ compensation point of leaf was increased for pea, but decreased first and increased then for wheat. With the increasing duration of UV-C radiation, the antioxidant enzyme activities of both test plants increased first and decreased then, except that the POD activity of pea and SOD activity of wheat decreased gradually. All of these suggested that wheat had a stronger resistance to short-time UV-C radiation than pea, but, with the prolonged duration of UV-C radiation, the photosynthesis and antioxidant enzyme activities of wheat and pea were all decreased.

Key words: Winter wheat, Dry year, Irrigation and nitrogen application, Physiological characteristics, Interactive effects, Yield factors