Effects Of DPR On Nitrogen Metabolism And Photosynthesis Characters Of Rice In Various Soils

The studies were conducted on the effects of double-promoting regulator (DPR) on rice key enzymes activities of nitrogen metabolism, rice protein contents of grain and brown rice and photosynthesis characters of rice in five soils. The results showed as follows:1 When DPR was sprayed in early rice and late rice during reproductive stage of rice growth, it could improve chlorophyll contents and net photosynthetic rate of functional leaves.2 The decrease trend of the contents of total N and protein N in functional leaves and stem-sheaths of early rice and late rice were observed during reproductive stage of rice growth. And their magnitudes of decrease were higher in DPR than CK. The increase trend of the contents of total N and protein N in grain of early rice and late rice were observed during reproductive stage of rice growth. And their magnitudes of increase were higher in DPR than CK. In addition, the contents of total N and protein N in grain of early rice and late rice in total filling stage were higher in DPR than CK.3 When DPR was sprayed in early rice and late rice during reproductive stage of rice growth, it could strengthen activities of nitrate reductase (NR), glutamine synthetase (GS), glutamine transferase (GT) and protease of functional leaves and glutamine synthetase (GS) and glutamine transferase (GT) in grain of early and late rice.4 The significant differences of total N and protein N of brown grain of early and late rice were observed between DPR and CK. The contents of total N in brown grain of early and late rice were 1.16-2.30 g.kg-1 and 1.35~2.63g.kg-1 higher in DPR thanCK respectively. The contents of protein N in brown grain of early and late rice were 1.07~2.22g.kg-1 'and 1.30~2.58g.kg-1 higher in DPR than CK respectively. On the other word, compared with treatments CK, the contents of raw protein in brown grain of early and late rice increased 6.90-13.68 g.kg-1 and 8.03-15.58 g.kg-1 respectively, the contents of protein increased 6.37-13.21 g.kg-1 and 7.74-15.35g.kg-1 respectively .The yield of grain of early rice and late rice of treatment DPR increased 1.98%~10.39% and 1.28%~4.52% than CK respectively. The significant differences of the protein yield in grain of early rice and late rice were observed between DPR and CK. And the protein yield in grain of early and late rice of treatments DPR increased 12.77%~16.56% and 8.39%~13.18% than CK respectively.