DISTRIBUTION DYNAMICS OF NITROGEN ABSORBED AT THE EARLY FLOWERING STAGE OF SWEET PEPPER (CAPSICUM ANNUUM L.)
甜椒始花期吸收的氮素在体内的动态分配规律

Sweet pepper ( Capsicum annuum L.) grown under water condition was used to study the distribution dynamics of nitrogen absorbed at the early flowering stage using 15 N tracer. The results obtained are as follows: The accumulation dynamics of vegetable organ dry matter display a rapid linear increase, and the fruit topped the other organs from the earlier profuse fruiting stage. The nitrogen concentrations were keeping steadily at same levels in root and fruit from the early picking stage. In the leaves, it decreased rapidly with development and was not much different from the root and fruit at the profuse fruiting stage, but had twice the concentration of the stem and branch. The nitrogen accumulation dynamics were similar to the dry matter. Most of the labeled nitrogen absorbed at early flowering stage by the roots was distributed and reserved in the leaves. It was found that about half of the labeled nitrogen absorbed at early flowering stage was transported to the neonatal part of the plant after two weeks and the translocation of absorbed labeled nitrogen began to decrease significantly after 4 weeks. After 6 weeks there was little of labeled nitrogen to be transported into the neonatal part of the plant. Newly absorbed nitrogen was transported into the other stronger parts of the plant more easily and with a higher reutilization rate. The longer the nitrogen existed in the organs of the plant, the lower the reutilization rate. The fruit has the most competitive ability for nitrogen among the different organs of the sweet pepper plant during the fruit harvest period. On the whole plant level, the transport of the labeled nitrogen from vegetative organs to the reproductive organs is affected not only by the intensity and capacity of the nitrogen sink competition, but also by the transport time for the labeled nitrogen absorbed at the early flowering stage.