抄録
1. Changes of pH value and nutritional interrelationship of Ca, Mg and K in shell were investigated to study the function of Ca by using Chiba 74 (runner type) in sand culture with the root and fruit zones isolated from each other. As to the pH value at the early stage of the filling, no difference was detected between the nornral and Ca deficient shells, but the value in Ca deficient shell, especially in abortive pod (namely the one which ceases to develop at the stage of pod enlargement), was markedly lower than that of the normal one in the filling process (Fig. 1). The reciprocal relation among Ca, Mg and K was very distinct in their total amount at each stage of the filling; fractional analysis of them indicated that each amount of HAc-sol-Mg and alc-sol-K was in an inverse relation to the amount of HCl-sol-Ca, and that there was a little difference in the amount of both of HAc-Sol-K and alc-sol-Mg between the normal shell and the Ca deficient one (Fig. 2). 2. The distribution and rise or fall of the contents of sugar, starch, and activity of some enzymes (amylase, phosphorylase, invertase, hexokinase and phosphatase), which are related to the metabolism of carbohydrate, were determined with above samples. The contents of reducing sugars in normal shell increased until around the 20th day after gynophore reached fruiting zone, but decreased rapidly thereafter. The same increasing trend and a very slower decreasing trend were observed in shell of empty pod, and its contents in abortive pod scarcelly ever changed at any time. The contents of non-reducing sugars of shell of empty pod were higher than those of normal one, and those of abortive one decreased considerably during the filling process. On the contrary, the very rapid accumulation of starch took place in abortive one, and starch content in Ca deficient shell was higher than in normal one at every stage (Fig. 3). The activity of five enzymes found in shell, which ripened under the condition of Ca deficiency, was higher rather than that of the normal one, but the activity per unit protein-N was remarkably lower, excepting the activity of invertase (Fig. 4, 5).
