水稲品種の耐肥性に関する研究 : 第1報 品種の耐肥性と窒素及び炭水化物代謝との関係

抄録

In Japan, it is very important for rice breeding to investigate the varietal adaptability of the plant for heavy manuring. In the present paper both nitrogen and carbohydrate metabolism are investigated under three levels of nitrogen application using three varieties for the purpose of elucidating the physiological mechanism of varietal adaptability for heavy manuring, Norin 25 (suitable for heavy manuring), Chiba-asahi (less suitable than the former) and Ginnen (Indica type and the least suitable one). The unsuitable variety shows a greater increase in nitrogen, especially in soluble nitrogen content, and greater decreases in sugar and starch contents than the suitable one with increasing supply of nitrogen. Such differences as seen in nitrogen and carbohydrate metabolism between the suitable variety and the unsuitable one may have brought a smaller increase or rather a decrease in the grain yield of the former as compared with the latter when they are supplied with increasing amounts of nitrogen.