Abstract
The present paper is concerned with the changes in nitrate content and nitrate reductase activity of carrot plant during the periods of growth and post harvest storage. Nitrate content of carrot plant was higher in petioles than in the other parts of the plant during the period of growth. In the middle stage of growth, the nitrate content in petioles was three times greater as much than in leaflets and six times as much than in roots. Activity of nitrate reductase was higher in leaflets than in petioles or in roots.
Nitrate content of carrot plant harvested at younger stage and at commercial harvest-stage showed no change during storage except for a little decrease in petioles. Nitrate reductase activity in leaflets during storage showed a marked decrease in the early period of storage and gradually decreased there-after, but no change in the activity was found in petioles and in roots during storage.
Under the condition of controlled atmosphere (CO2=3%, O2=3%) at 0°C, the content of nitrate in carrot roots was smaller than under the atmospheric condition in the earlier period of storage, but there was no difference in nitrate contents in such treatments in the latter period of storage.
The ascorbic acid contents of carrot plant during growth and post harvest (storage) periods were also determined with reference to the change in nitrate content, but there was no correlation between contents of the two compounds.
