STUDIES ON THE CONCENTRATION CHANGE OF HYDROGEN-IONS AND POTASSIUM-IONS IN A CULTURE SOLUTION DURING THE GERMINATION AND GROWING PERIOD OF RADISH

The behavior of hydrogen ions and potassium ions in a culture solution was examined during germination and growing period of radish (Kaiware daikon). The radish was grown in the culture solution made up of pure water or in the solution containing potassium chloride. The germination rate was ca. 80 approximately 90%. During the germination period (ca. 20h) from the seed snow in the culture solution of pH 6, 5 and 4, the concentration of hydrogen ion shifted to ca. pH 7 with the passage of time, and the concentration of pottassium ion increased from zero up to 10(-4) mol/dm3. On the other hand, in the growing period (ca. 1 week), radish absorbed almost all potassium ion liberated in the germination period and liberated hydrogen ion. Next, in order to examine the influence of concentration of potassium ion in the culture solution, the radish was grown at pH5 in solutions containing potassium ion of concentration ranging from 10(-5) to 1 mol/dm3. The results showed that the incorporation of hydrogen ion was suppressed with the increase of the potassium ion concentration. However, when potassium ion becomes more than 0.1 mol/dm3, the radish was poorly germinant and not entirely grown. The correlation coefficient of correlation between hydrogen and potassium ion concentrations in the culture solution was between -0.84 approximately -0.96, and a good negative correlation was observed between them.