Study On The Physiological Mechanism Of Nitrogen Metabolism And The Grain Filling Of Liangyoupeijiu At The Late Development Stage

It's key fanctors for seeding ration and saturation degree of grains that the photosynthetic characteristics, absorption, transportation and assimilation of nitrogen in flag leaf, the root activity and filling characteristics of grain the late development stage. Therefore, it has very important theoretical and practical significance that researching on the nitrogen metabolism in leaf and root, and the grain filling characteristics of "liangyoupeijiu" during the late development stage. The nitrogen metabolism and grain filling characteristic of "liangyoupeijiu", "9311" and "shanyou63" was studied in this peper.The results showed that the changes of activities of the NR, GS, GDH and proteinase in flag leaf guandually rose at earlier filling stage, and then declined. Compared with "shanyou-63"and "9311", the activities of enzymes above-mentioned in flag leaf of "liangyoupeijiu" declined fastly. The change tendency of the GS, GDH, GPT and GOT activities in root were the same as that of those in leaf. Compared with "9311", the activities of enzymes above-mentioned in root of "liangyoupeijiu" were remarkable lower. The decline of the activities of those enzymes in root was earlier than that of those in leaf for one week. These results showed that the physiological activity of "liangyou-peijiu" declined earlier, which might be the importantal reason that earlier decline of the synthetical capacity in overground part. The dynamics of the NR,GS and GPT in leaf and root showed that the changes of enzymes activity were not i n agreement with whose Kms during filling stage. Therefore, Km of enzyme is not the only factor that leads to the decline of its activitiy, the contents of the enzyme protein may also an important influence factor.The SS, SPS ctivitiy and photosynthetic rate in flag leaf rose at earlier filling stage and then declined, but the contents of the chlorophyll, soluble sugar and starch, and the activity of the ATPase in flag leaf declined slowly after blossom. During the filling stage, compared with "shanyou63"and "9311", the SS, SPS and ATPase activity, the contents of the chlorophyll, soluble sugar and starch, and the photosynthetic rate in flag leaf of "liangyou peijiu" declined rapidly, which led to quantities of the physiological indexes above-mentioned of "liangyoupeijiu" lower than that of the "shanyou63" and "9311". The results that studied on the amount of bleeding and the contents of soluble sugar and amino acid in bleeding sap showed that the root physiological activity of "liangyoupeijiu" was lower than that of "shanyou63". Compared with "shanyou63" and "9311", the ability of assimilation and conversion in root for "liangyoupeijiu" declined earlier for one week, which was in agreement to the lower enzyme activities in root. The results of research on the ATPase, SS and SPS activity, the contents of the soluble sugar and starch, and the characteristics of the grain filling in vigorous grains showed that the three varieties had no remarkable difference. However the starting stage of the grain filling in the weak grains of "9311" was earlier than that of "liangyoupeijiu" and "shanyou63".The grain filling of "9311" is continuous, in contrast, "liangyoupeijiu" and "shanyou63" are belonging to the varieties which have remarkable characteristic of discontinuous grain filling. Comparing with "shanyou63", "liangyoupeijiu"is in further more remarkable characteristic of discontinuous grain filling. The significant positive correlation was in among the grain filling rates, the contents of the soluble sugar and the SS activity in vigorous grains for the three varieties. However, we had not found the same relations in weak grains. The got results showed that the vigorous grains have strong abilities of nutrient uptake and assimilation. The ability of material conversion and transformation of the source remarkably influence the filling rate of vigorous grains. But it's more complex in weak grains. Except the activities of material conversion and transformation of the source, the capacity of nutrient uptake and assimila tion of weak grains are also closely related to the filling rate of weak grains.Comparing with "9311"and "shanyou63", the ability of assimilation and transformation of "Liangyoupeijiu" declined rapidly, which closely related to the earlier decline of the capacity of absorption, assimilation and transportation in root. The startup in late and the lower rate of grain filling lead to long filling time of weak grains for "Liangyoupeijiu", which closely relates to the ability of nutrient uptake and assimilation of weak grains. Therefore, when "Liangyoupeijiu" had senesced, and the capacity of material conversion and transformation of source declined, the grain filling had not still finished, which restricted the taking advantage of super high yield potential.