In order to determine the differences of nitrogen metabolism of different rice cultivars under different cultivations, field plot experiments were carried out for two years in Hunan. The results show that total N contents and protein N contents in leaves, stem-sheaths, seeds, brown rices of high-protein convention rice Xiangzaoxian 24 and high-protein hybrid Weiyou 56 are obviously higher than those of low-protein convention rices Xiangzaoxian 13 and Zhongyouzao 81, and low-protein hybrid Jingyou 974. Nitrate reductase activities and glutamine synthetase activities and protease activities in f...
