Abstract
We investigated the effects of nitrogen on rice plant height, the number of tillers and ears, culm length and number of grains of different gibberellin levels following treatment with gibberellin (GA_3) and a gibberellin biosynthesis inhibitor (uniconazole-P). Nitrogen made the characteristics increase. GA_3 increased plant height, culm length and number of grains per ear and decreased other characteristics. GA_3 and uniconazole-P had the opposite effects. These results suggested that the increasing effect of nitrogen on plant height and number of grains per ear was connected with the increasing gibberellin level, however the effect of nitrogen on the number of tillers and ears was not caused by gibberellin, because the number of tillers and ears increased under the low gibberellin level by uniconazole-P treatment.
