Studies on the Physiological Nature of Sweet-Potato Plants : (IV) On the Variations of Nitrogen Compounds in the Seed Tubers during the Hot-Bed Nursery Period

Abstract

In order to obtain some informations on the behavior of translocation and storage of nitrogen compounds in the seed tuber of sweet potatoes during the hot-bed nursery period, the present investigation was undertaken with the variety "Gokoku" as material. The experimental results obtained may be summarized as follows: 1. At the sprouting stage of the seed tubers, the protein-N contents fluctuated slightly, while the soluble-N contents increased considerably; and consequently the total-N contents became larger as compared with those at the time of imbedding. 2. Being accompanied with the deveolpment of sprout, both the protein and sluble-N contents decreased remarkably, which in turn caused a rapid falling of the total-N contents in the seed tuber. 3. In the later stages of growth in the hot-bed nursery, both the protein-and soluble-N contents increased steeply and the total-N contents rose consequently.