| In this research, the dynamics of dry matter and nitrogen in soybean plant were systematically investigated, using DN163, an advanced high oil selection, as plant material in order to probe the physiological mechanism of nitrogen accumulation in high oil soybean, and to provide the theoretical basis of agronomic measures for high quality and high profit. The results are as follows.Dry matter accumulation in the leaf, petiole, and stem peaked in the period from fruiting to filling. In the early stage of growth, the growth center was in leaf, turned gradually to both leaf and stem, and then legume. Nitrogen accumulation was correlated to dry matter accumulation. In the early stage, less nitrogen was accumulated. Afterwards, nitrogen accumulation increased with increase in the growth rate of plant and dry matter accumulation.The nitrogen content in soybean plant changed as a curve, with the maximal value being at flourishing fruiting period. There was difference in the nitrogen content among different organs, and leaf contained more nitrogen than petiole and stem did. The nitrogen content in leaf changed also as a curve, the maximum being at flourishing fruiting period, while the nitrogen in petiole and stem decreased slowly with the growth of plant. The nitrogen content in legume increased steadily after filling stage. The positions at which the leaf was borne on a plant had an effect on the nitrogen content. The nitrogen content in the leaf from top to lower part increased and then decreased, whereas in the petiole the reverse was true.The dynamics of ammonia nitrogen was different among leaf, petiole, stem, and legume. The ammonia nitrogen in leaf and legume decreased with the process of growth. The change of ammonia nitrogen in stem was as a curve, with the maximal value being at the early filling stage. The ammonia nitrogen content in petiole was low at seedling stage, increased until flowering stage and then decreased with minimal value being at fruiting stage, and finally increased again. The position of leaf on a plant had an influence on ammonia nitrogen content. At the stages, seedling, flourishing flowering, and early filling, the middle leaves contained more ammonia nitrogen, while top and low leave less. In the filling stage, the ammonia nitrogen content decreased in the leaves from top to low part. For petioles, the ammonia nitrogen content was high in the top and low leaves at flourishing flowering stage, and low in the middle. In the filling stage, ammonia nitrogen content decreased from top to low leaf. Nitrate nitrogen was mainly accumulated in petiole and stem, and it decreased with the growth of plant. In the early stage of growth, the petiole held a high level of nitrate nitrogen. In the early filling stage, it began to decrease sharply and was lower in petiole than in stem. For thedistribution of nitrate nitrogen in different leaves on a plant, in the seedling stage up leaves were low in nitrate nitrogen content compared with low leaves. In flourishing flowering stage, the nitrate nitrogen content increased until the fourth leaf from the top, and then began to decrease. In early filling stage, the first leaf from the top contained a very low level of nitrate nitrogen. The fifth and sixth leaf contain a high level of nitrate nitrogen, and the content in the second to fourth and seventh to eleventh leaf was similar, but lower than in the fifth and sixth.Ureide was found in stem, leaf, petiole, and legume. The content of ureide was much higher in stem than in leaf and petiole. Leaf was higher in ureide than petiole. During the period of R1-R6, ureide changed as a curve with a single peak appearing at the flourishing flowering stage. The percentage of ureide in stem and petiole began to increase at the early flowering stage. From flourishing flowering stage onwards, the percentage of ureide ranged from 62% to 68% in stem, and 22% to 34% in petiole, suggesting that the nitrogen in leaf was from inorganic nitrogen absorbed from soil by roots, not from nitrogen fixed by rhizobium, t... |
PDF Full Text Request