Abstract: To advance our understanding the effects of light regimes on photosynthetic characters and yield components, and comparison the difference between sweet and waxy maize, two genotypes of maize, Xiangbainuo and Yuetian 3, were planted by artificial shading. These two genotypes of maize were raised under three light regimes: 100% of sunlight, 80% of sunlight, and 40% of sunlight for their whole life long. Leaf photosynthetic characters (Pn and Tr), chlorophyll fluorescence parameters (Fv/Fm and Φ_SⅡ), and photosynthetic pigments content (Ch1 a, Ch1 b and Car) were determined. Yield components were also measured. The results showed that rates of apparent photosynthesis and transpiration were reduced significantly by shading, however, there was no significant difference between the two genotypes of maize. Fv/Fm in the two genotypes of maize increased with decreasing light intensity in seedling and grain filling stages. At the same light regimes, Fv/Fm in Xiangbainuo was much higher than that in Yuetian 3 in seedling stage, but lower in grain filling stage. With decreasing light intensity, Φ_SⅡ in both Xiangbainuo and Yuetian 3 increased in seedling stage, decreased in grain filling stage. Bald length was much longer in two genotypes of maize by shading. The main effects of week light regimes leaded Pn and Tr of sweet and waxy maize reducing significantly. There was week light stress on both sweet and waxy maize, thought there was difference between the two genotypes of maize. The significant decreasing of ear length, kernels per row and weight per ear under week light regimes were the main reasons of yield reduction.

Key words: Light regimes, Photosynthesis, Yield components, Sweet maize, Waxy maize

CLC Number: 

• S513.01