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

Abstract

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.