Growth and chloride accumulation in soybean cultivars treated with excess KCl in solution culture

Sensitivity to chloride was measured in soybean [Glycine max (L.) Merr.] cultivars Rinjani, Lokon, and Merbabu from Indonesia, and Lee from the United States. Plants were grown in solution culture to which KCl (0, 50, or 100 mol m(-3)) was added gradually during days 7-14 after emergence. Excess KCl reduced growth, measured as leaf area, shoot and root biomasses, total biomass, and root/shoot ratio in 24-day-old plants of all cultivars. The cultivar x KCl treatment interaction was significant for all growth parameters. The order of chloride tolerance at 50 mol m(-3) Cl-, based on the mean of all growth parameters relative to the control, was Lee>Rinjani>Lokon=Merbabu. In the 50 mol m(-3) Cl- treatment Lee excluded Cl- from the leaves, and accumulated Cl- in the roots; Lokon, Rinjani, and Merbabu excluded less Cl- from the leaves. At 100 mol m(-3) KCl, cultivar Lee lost its capacity to exclude Cl- from the leaves and its growth was poor. Chloride exclusion from the leaves at 100 mol m(-3) KCl was most effective in Lokon, which corresponded to the relatively good growth of this cultivar in the high KCl treatment.