Potassium uptake kinetics of potato, wheat and sugar beet plants as affected by the k nutritional status
2001
Trehan, S.P. (Central Potaoto Research Station, Jalandhar (India)) | Claassen, N. (Georg-August-Universitat, Gottingen (Germany).Institut fur Agrikulturechemie)
In an earlier work potato showed a smaller K influx than wheat or sugar beet. In the present study K uptake kinetic parameters i.e. maximum influx (Imax), the Michaelis constant (Km) and the minimum concentration (Cmin) were measured for potato and wheat plants (28 days old) and for sugar beet plants (23 days old), in order to elucidate the basis of these differences. These plant were grown at constant concentration of 1.5, 15 or 200 æM K in flowing solution prior to start of depletion. Imax was higher in plants grown previously at low K concentration than in plants grown at higher K concentration for all the plant species. Imax was negatively correlated to extent of K sufficiency (shoot K concentration expressed as % of minimum required for maximum shoot growth rate of each species) irrespective of plant species. In contrast to the hypothesis K uptake kinetics parameters of potato were similar to those of wheat and sugar beet at the age of their measurement. This contradiction seems to be based on the fact that potato became adapted to a low K supply by improving its uptake kinetic parameters, mainly the Imax value with time. In this way after 4 weeks of adaptation potato had reached a similar uptake capability per unit of root as the other species.
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