Nitrogen metabolism of different rice varieties to nitrogen fertilization

• Main Authors: Yuh-Chang Shyu, 徐毓昌
• Other Authors: Ching-Yih Chen
• Format: Others
• Language: zh-TW
• Published: 1995
• Online Access: http://ndltd.ncl.edu.tw/handle/47152819068442964917

碩士 === 國立中興大學 === 植物學系 === 83 === Measurement of diurnal changes of stomatal movement indicated that stomates opened at about half past seven in the morning and apertures were increased rapidly . The maximum aperture opening was around nine o'clock in the morning and maintained opening until two o'clock in the afternoon .The stomatal began to close about two o'clock in the afternoon and apertures were decreased rapidly. The stomatal almost completely closed about four o'clock in the afternoon and no night opened phenomenon was observed . Both fertilization treatments have greater degree of stomatal aperture than no fertilization ones. Both fertilization treatments had greater total chlorophyll contents than no fertilization. Because of this, Tainung 67 , Taikeng 2 and Woogen had greater oxygen evolution rates under fertilization. So fertilization can increase total chlorophyll contents and rise the rate of photosynthesis.However , Taiseng 1 had no differences in the oxygen evolution rate with different nitrogen treatments. Fertilization increased the photosynthesis rates as well as Rubisco activities resulted in accelerating whole carbon metabolism . It's that achieves carbon and nitrogen equilibration thereby accelerates nitrogen metabolism . So increased nitrate reductase and nitrite reductase activities were observed under fertilization. In higher plants, ammonia is mainly assimilated by GS/GOGAT pathway which produces glutamine and glutamate . Addition of ammonium salts via fertilization should produce higher amount of glutamate due to the increased enzyme activities in the GS/ GOGAT pathway . Our results showed that indeed glutamate had the highest content among 20 amino acids of all four rice varieties .