Potassium Release and Uptake in Germinating Legume Seeds in Relation to Seed Condition and Germination Environment

Abstract

The levels of K+ and total electrolyte leakage into leaching solution from imbibed seeds of Pisum sativum L. and Phaseolus vulgaris L. have been followed to determine the relationship of K+ loss to the level of total electrolyte loss, and its relation to the physiological condition of the seed. The extent and rate of loss of both K+ and total electrolytes varied with both seed condition and the conditions imposed by the experiment. K+ accounted for between 25 and 50% of the total electrolyte leakage. The relationship was at all times significantly correlated, but changed with time and with experimental conditions. The effect of immersion, which increased electrolyte leakage due to soaking injury, masked differences in seeds of varying field performance. Imbibition at either 5 °C or 40 °C before leaching was shown to increase both K+ and total electrolyte loss in comparison to seeds imbibed at 25 °C. These results suggest that the 'conductivity test', which is used as a measure of seed deterioration, may need to be re-examined in terms of experimental procedure and interpretation.