Physiological and Morphological Studies on Potato Plants : Part 18. On the influences of nature and of age of seed tubers on some physiological behaviors at the time of sproutiong of the tubers

Abstract

With a desire to see the variations in ascorbic acid content, and in amylase and phosphorylase activities at the time of sprouting of potato tubers, the present investigation was carried out. At the sprouting period of the normal and greening potato tubers, ascorbic acid (especially reduced form) contents decreased remarkably, which in turn caused striking rise of amylase activity, while the phosphorylase activity falled gradually. Judging from these results, it may be assumed that the enzymatic degradation of reserve starch in potato tubers may be hydrolytic, as catalyzed by amylase system, rather phosphorylytic, as catalyzed by phosphorylase system. on the other hand in the old tubers, owing to the senility of the tubers, lowering of ascorbic acid content and of amylase and phosphorylase activities were recognized.