Comparison of the Nutrient Uptake in Ecospecies and Ecotypes of Rice Seedlings

[摘要] The experiment was conducted to evaluate the difference in nutrient uptake of different ecospecies and ecotypes of rice plant. Fifty one japonica cultivars composed of 32 lowland and 19 upland cultivars, and 25 indica lowland cultivars were used. The uptakes of ammonium-N (NH4-N), nitrate-N (NO3-N), phosphorus and potassium (in nutrient mg·dry wt g-1·h-1) were determined by using 25-day-old seedlings. The result revealed that : (1) Ammonium-N and phosphorus uptakes were higher in indica compared with japonica. On the other hand potassium uptake was higher in japonica than in indica. There is no difference between the two ecospecies in nitrate-N uptake. (2) Lowland rice showed higher uptake than upland rice in four nutrients, especially in nitrate-N and potassium. (3) Nutrient uptake was in the order of: nitrogen, potassium, phosphorus. This order of uptake was consistent on ecospecies and ecotypes. (4) Correlations between dry weight and potassium uptake, and between ammonium-N and nitrate-N uptake, phosphorus uptake were not significant japonica, but positive and significant in indica. Correlation between root number and ammonium-N uptake was not significant in upland rice, but negative and significant in lowland rice. (5) Nitrate-N uptake showed a positive and significant correlation to potassium uptake regardless of ecospecies and ecotypes. (6) It can be concluded that inorganic assimilation of rice plant depends on the ecospecies and ecotypes.

[学科分类] 农业科学（综合）

[关键词] Ammonium-N;アンモニア態窒素;Nitrate-N;イネ;Nutrient uptake;カリウム;Potassium;Rice;硝酸態窒素;養分吸収