Effect of Temperature on Rice Chalkiness Formation and Changes of Materials in Endosperm

Under two treatments of temperature i. e. high temperature (day/night: 33℃ /29℃ ) and proper temperature (day/night: 26℃ /22℃ ) in growth chamber, grain weight, water content, starch, soluble sugar and protein content and Q enzymes, starch phosphorylase, proteinase, peroxidase in endosperm during grain filling were continuously measured in early indica rice Luhongzao 1 (more chalkiness ) and Zhongyouzao 3 (less chalkiness ).With high temperature treatment, peaks of materials synthesis (or transformation) and enzyme activity in endosperm were earlier than those of proper temperature treatment. It affected the sequence and pattern of changes of materials and enzymes in endosperm during normal grain filling, and resulted in rice chalkiness increasing.