Effect Of Nitrogen Application An Transplanting Density On Protein Content And Rice Quality In Cold Japonica Rice

Rice is seen as the main food crop in the world,and resonnably applying nitrogen fertilizer and establishing the group structure will be the most important foundation of high-yielding rice。In this paper,three japonica cultivars Mudanjiang30、Dongnong426 and Songjing14 were field-grown as materials,and four dealing methods of nitrogenous fertilizer(with no nitrogen, fertilizing 75 kg,150 kg,225 kg pure nitrogen in each hectare field),and three planting density treatment(D1:30cm×16.6cm、D2:30cm×13.3cm、D3:30cm×10.0cm). To discuss the kinds of activities for NR, GS and Transaminase(GOT and GPT) in different nitrogen application and transplanting density of rice and also discussed the effect of nitrogen absorption and utilization, the protein accumulation and formation, yield and quality of rice in different nitrogen application and transplanting density,afterwards it made clear the regulation mechanism of nitrogen metabolism on the application of nitrogen and transplanting density in cold japonica rice, aimed to provide theoretic foundation and technical support for japonica rice scientific and rational applying nitrogen fertilizer and establish a group structure. The following are the main results concluded from the experiment:1.The amount of nitrogen in the whole plant get lower and lower as the plant grows in Mudanjiang30、Dongnong426、and Songjing14. Three varieties of plant nitrogen uptake in early growth stage was little,then increased to a slight degree with the jointing stage,and then rapidly increased after heading,and got to the highest level when it is mature. Mudanjiang30’s plant nitrogen ratio and nitrogen uptake of N3D2 were the high est, Dongnong426 and Songjing14’s plant nitrogen ratio and nitrogen uptake of N3D3 were the highest. Three varieties had a more balanced source of nitrogen in grain.2.Mudanjiang30 and Songjing14’s nitrogen absorption efficiency with N2D3 was at the highest level, while Dongnong426’s nitrogen absorption efficiency with N3D2 was at the highest level. Three sorts of nitrogen physiological efficiency were at the highest level with the combination of N1D3. Mudanjiang30’s nitrogen agronomy efficiency of N1D2 was the highest, Dongnong426 and Songjing14’s nitrogen agronomy efficiency of N1D3 was the highest.3.For the three varieties, the overall activities of NR and GS in functional-leaves change as a single peak curve as the whole growth period of time went on, and reached the peak both in Heading stage.Three varieties within heading stage 7~35d for grain transaminase activity in the process of changed: GOT activity showed a single peak curve changes, and got to the top point in heading stage 14d; and GPT activity was sort of "reduce-up-reduce" change, and reached the maximum in heading stage 21 d. Mudanjiang30’s NR and GS enzyme activity were the highest in N3D1 combination,what’s more, transaminase activity showed it was the highest when N1D2 combination happened; Dongnong426’s NR and GS enzyme activity were the highest in N3D2 combination,and in others words,transaminase activity presented the highest point when N2D2 combination happened; Songjing14’s NR enzyme activity was the highest in N3D2 combination,and the activity of GS enzyme reached the highest point when N3D1 combination happened,and transaminase activity got to the highest point in N2D3 combination.4.For the three varieties, the amount of soluble protein in functional-leaves changed as the only top point curve within the whole period of growth, and got to the top point both in Booting stage,and with the application of nitrogen increased, the amount of soluble protein increased quickly and apparently,but instead the effect of planting density was not apparent.Three sorts of grain protein amount were the highest for 7d after the heading stage, and then went down rapidly, after the heading stage 21 d dropped to the lowest, followed by a slow recovery, but the increase rate was smaller. Three varieties’ soluble protein and grain protein content were the highest in N3D1 combination.5.Three varieties’ yield and protein yield had significant difference between nitrogen and density, the best handling method for Mudanjiang30,Dongnong426, and Songjing14 were N2D1, N3D2, N3D3, respectively.6.Three sorts’ milling quality within a certain range together with the increase of nitrogen application increased apparently, and got to a high point as the planting density was getting larger; Chalkiness and the percentage of chalkiness degree of the overall together with the increasing use of nitrogen and planting density got larger rapidly; Amylose amount together with the increasing application of nitrogen and planting density went down; Gel consistency overall went down with the increasing amount of nitrogen application, got to a big number as the planting density increased; Protein, lysine and tryptophan amount together with the increasing application of nitrogen went up, under the same nitrogen level, protein amount would decrease as the planting density increased.