Studies on the Floating Rice : IV. Effects of raising water level on the nitrogenous compounds of the tops

[摘要] In one experiment, several varieties of floating and non-floating rice plants were grown under submerged condition by raising water level as described in previous report. Total-, protein-, total soluble-, and amide plus ammonia-nitrogen of the floating and non-floating rice plants were compared with those under ordinary condition. In another experiment, Co. 64 and Norin No. 22, the floating and non-floating rice plant respectively, were grown under submerged condition by raising water level and then lowering it. The various fractions of nitrogenous compounds of the leaf blade, leaf sheath and internode grown under submerged condition were compared with those under ordinary condition. The results obtained were as follows: 1. Under ordinary condition, there were no significant differences in the contents of total-, protein-, and amid plus ammonia-nitrogen between the non-floating and floating rice, but the content of total soluble-nitrogen was slightly higher in the floating rice, while concentrations of total-, protein-, and total soluble-nitrogen were higher in the non-floating rice. 2. The content of protein-nitrogen of the non-floating rice was decreased, but that of the floating one was increased under submerged condition. Concentration of protein-nitrogen decreased in both types of plant by submerging treatment. 3. Both content and concentration of total soluble-nitrogen in the non-floating rice was increased under submerged condition, while those of the floating rice showed no appreciable change. 4. The content of amide plus ammonia-nitrogen was increased markedly under submerged condition in both the non-floating and floating rice, especially in the former. Amide plus ammonia-nitrogen concentration of the non-floating rice was increased more markedly as compared to that of the floating rice. 5. The nitrogenous compounds of the leaf sheath and internode were more affected by submerging treatment than that of leaf blade. The ratios of total soluble-nitrogen or amide plus ammonia-nitrogen to protein-nitrogen became larger under submerged condition in the non-floating rice, while the change of the ratios remained narrow in the floating rice. These results may show that the floating rice maintains the normal nitrogen metabolism under both ordinary and submerged condition.

[学科分类] 农业科学（综合）