biologia plantarum

Biologia plantarum 29:221-229, 1987 | DOI: 10.1007/BF02876834

Diurnal variations of potassium content in lucerne plants

F. Plhák¹

¹ Research and Breeding Institute for Fodder Plants, Plant Breeding Station Želešice, Želešice (Brno), Czechoslovakia

Diurnal changes in K content in leaf blades, petioles, stems and roots of eleven lucerne genotypes were followed. Significant positive correlations between changes in K content in petioles and upper half of stems and significant negative correlations between changes of K content in leaf blades and lower half of stems reflected rapid K movement. The velocity - up to 60 μmol g-1 (f.m.)h-1 - of changes in K content from leaf blades to lower part of stems and the other way round showed that long distance phloem transport occurred. Only moderate increase of K content contemporarily took place in roots. When total K amount in the whole plant was calculated then K uptake alternatively with K release were noticed during the day. Average K release reached 1.48 μmol g-1 (f.m.) h-1. The rate of K movement correlated with irradiance and physiological activity of plants. The time course of K movement was uniform in plants of the same strain and it differed partially in different strains.

Received: April 2, 1986; Accepted: September 16, 1986; Published: May 1, 1987  Show citation