Abstract:

The global climate is getting warmer and warmer with the wide use of chemical and petroleum fuels. The experiment was conducted using maize cultivars Nongda 108 and Shannong 3 with the treatments of increased air temperature at three different growing stages in growth-chamber set up in the field condition, and the yield, the content of starch and the activities of the key enzymes in starch synthesis of maize kernels were determined. The results indicated that the first high air temperature treatment at the first stage (0–28 days after the emergence of seedling) had almost no effect on grain yield, the second one (29–57 days after the emergence of seedling) and the third one (58–86 days after the emergence of seedling) decreased the yield in maize significantly. Among them, the second one had a sharp decrease in yield, by 23.8% on an average. Meanwhile, high air temperature treatment also decreased the activities of fruictose-1,6-diphosphatase (FBPase), sucrose phosphate synthase (SPS), starch synthase (SS) and adenosine diphosphate glucose pyrophosrylase (ADPGPPase), and with the largest decrease in the second high temperature stage. As to the starch content in grains, there were no influence of high air temperature treatment at the 1st stage, and negative influence of high air temperature treatment at the 2nd and 3rd stages. Postponing sowing date and selecting heat-resistant cultivars were suggested to relieve the influence of high air temperature on maize.

Key words: High air temperature, Starch synthesis, Yield, Maize (Zea mays L.)