The Variation of Biomass and Photosynthesis of Different Maize Inbred Lines and Hybrids to Enhanced Ultraviolet-B Radiation

Abstract

Enhanced ultraviolet-B (UV-B) radiation has potentially harmful effects on terrestrial plant growth and development. To examine the effects of enhanced UV-B radiation on growth and photosynthesis, four elite maize inbred lines and their hybrids were irradiated with UV-B in glasshouse for 0h,2h,4h and 6h per day, a total of four days treatment. Under enhanced UV-B radiation, the fresh weight, dry weight, net photosynthetic rate and Fv/Fm of six maize seedlings were inhibited in a dose-dependent manner, with greater inhibition at the high dose. Among four maize inbred lines, Zheng58 was tolerant and Chang7-2 was susceptible to UV-B radiation. In two hybrids, Nongda108 was significantly superior to Zhengdan958 under three different UV-B treatments. The results showed that the responses of six materials to enhanced UV-B are not only inbred-specific but also hybrid-specific, and there exhibits the heterosis in crosses of maize inbred lines under enhanced UV-B.