Grass pea is a legume with great potential for use in both human food and animal feed. This study was performed to determine the tolerance of ten grass pea genotypes in cadmium stress condition, based on dry matter accumulation at callus and seedling stages under in vitro conditions. The calli and seedlings were exposed to various cadmium concentrations (0, 12.5, 25, and 50 µM). Callus cultures were grown on MS medium supplemented with 2,4-D (2 mg/L), and the seedlings were grown with BAP (1.5 mg/L). Both calli and seedlings survived at 50 µM cadmium, while 25 µM had no significant effect on their growth . At 25 µM cadmium, callus and seedling root growth were reduced by 50.41% and 35.27%, respectively. Hence, callus was less tolerant to cadmium than seedlings, likely due to its higher cadmium accumulation The present study suggests that grass pea exhibits high tolerance to cadmium, and can also surviving low to moderate concentrations of cadmium at seedling and callus stages. Tolerant callus lines may serve as valuable sources for regenerating cadmium-tolerant plants, which should be further evaluated for their detoxification potential at the adult growth stages.
