Genetic differences among wild oat lines in potassium uptake and growth in relation to potassium supply

Summary

Short-term (10min) K⁺ (⁸⁶Rb) influxes (φK⁺ _oc), rates of net K⁺ uptake (φK⁺ _net) and growth in relation to K⁺ supply were studied in genetically pure lines of wild oat. The wild oat lines employed in this study showed substantial differences in these traits. φK⁺ _oc was higher in the AN lines (AN5 1. AN 474) than CS 40 and SH lines (SH 319, SH 430) in plants grown under both low and high K⁺ conditions. Kinetic constants V_max and K_m for φK⁺ _oc, of selected lines and the rates of change of these constants with root K⁺ concentration ([K⁺]) showed that φK⁺ _oc in AN 51 was consistently higher than in CS 40 and SH 319. φK⁺ _net was also generally higher in AN 51. φK⁺ _net (at different growth stages), unlike φK⁺ _oc, failed to correlate with root [K⁺]; φK⁺ _net values were low during the first two weeks despite lower root [K⁺]. CS 40 showed the highest utilization efficiency, produced the largest amount of biomass, absorbed most K⁺ and flowered earliest (by day 30). AN 51 had not produced flowers at day 42.