水稲の塩害に関する研究 : XVI. 塩分処理による水稲体内の塩分, 窒素並びに炭水化物含量の消長について

抄録

The rice variety "Kyoto-Asahi" was grown in pots by sand-culture with the saline solution of various concentrations of from 0.1% to 0.6%. The amounts of chloride, nitrogen and carbohydrate accumulated in plants were titrated at approximately 10 day intervals from July 30 to Oct. 3. In plots of lower concentrations such as 0.1%-0.2% of salt, no significant difference was found from the control plot, or non-saline sclution, for the amount of each component. In the higher salt-concentration plots, particularly in 0.5-0.6%, the salt content in plants was much greater than that in control plot. The C1 percentage increased with the growth of plant to Aug. 21 (about young ear formation period), and then decreased with the progress of the generative growth. Thus the seasonal variation of C1 content is found, which may be probably connected with the pattern of the physiological activities of plant such as transpiration, absorption of water and nutriment etc. By the treatment of salt of higher concentration the amount of carbohydrate tended to decrease, and that of nitrogen increased at the former stage of growth. While the differences of the nitrogen content between the 0.3-0.4% treatment plots and the control were reduced so that no significance was found in the later stage after heading, the content of nitrogen in the 0.5-0.6% plots was obviously greater than that of plant in control plot until end of the stage. The differences of the carbohydrate content between treatment and control were greater with the progress of growth, and the accumulations in panicles of plants in treated plots were delayed and more scarce than in control plot, resulting the decline of yields. The injuries of growth and the damages of yield in rice plant caused by salt may be due to the physiological disturbance induced by the over-accumulation of nitrogen and the decrease of carbohydrate production.