Relationship between root respiration and ammonium concentration in rice plants concerned with inhibit of ripening.

本研究的目的是：（A）确定糙米中铵离子浓度与水稻粒重的关系;（B）在假定根呼吸降低时，根中铵离子不能与氨基酸同化的前提下，确定水稻茎基部伤流液中铵离子浓度与根系膨胀的关系。（A）水稻植株在盆中栽培，给予几种处理以抑制成熟（1990年），并在稻田中栽培不同肥料水平（1991年）。用酚法测定了小麦的干千粒重和铵态氮含量。抽穗后2 ~ 30天糙米铵态氮浓度与糙米重呈负相关。糙米铵态氮浓度与叶片含氮量呈高度正相关。结果表明，叶片含氮量高时，糙米中铵态氮浓度的增加会抑制粒重的增加。(B)It根系呼吸与茎基部伤流液铵态氮浓度的关系尚不清楚。但75%光照强度下的水稻植株铵态氮浓度却高达38 ppm。这个机制是目前要解决的问题。

The objectives of this study were(A)to determine the relationship between the rice grain weight and the ammonium concentration in the brown rice and(B)to determine the relationship between the ammonium concentration in the bleeding sap from the base of stem and root respiraton in rice plant on the hypothesis that if root respiration was decreased, ammonium in roots could not be assimllated with amino acid.(A)Rice plants were cultivated in pots given a few treatments in order to inhibit of ripening(1990)and in paddy field with different manure levels(1991). It was investigated to the dry 1000 grain weight and its ammonium concentration with phenol methods. It was found a negative correlation between ammonium concentration of the brown rice and its weight from 2 to 30 days after heading date. The ammonium concentration of brown rice showed a high positive correlation with the nitrogen content in leaves. It was concluded that when nitrogen content in leaves is high, the grain weight is been inhibit due to increase the ammonium concentration of brown rice.(B)It was not make clear the relaionship between the root respiration and ammonium concentration in bleeding sap from the base of stem. But its ammonium concentration of rice plants given shading of 75% light intensity showed very high as 38 ppm. This mechanism is the problem to be solved for the time being.