GROWTH AND CADMIUM ACCUMULATION IN 2 DURUM-WHEAT CULTIVARS

A solution culture study was conducted to determine the effects of cadmium (Cd) application on Cd accumulation and growth of two durum wheat (Triticum turgidum L. var durum) cultivars. Arcola and DT618 were grown in nutrient solution for 13 days. Cadmium application to nutrient solution significantly (P less-than-or-equal-to 0.05) decreased root and shoot biomass, leaf area, leaf mass, total root length, and chlorophyll a and b concentration of the first leaf. The deleterious effects of Cd on plant growth were explained by a modified version of Weibull distribution function of the form, y = a.exp(b. square-root Cd), where 'y' is the growth parameter, 'a' is plant growth in the absence of Cd, and 'b' is reduction in growth with per unit increase in solution Cd. Total root length was decreased the most (80%) and chlorophyll b concentration of the first leaf decreased the least (9%) with per unit increase in solution Cd. Although the two cultivars were significantly different in some growth characteristics, both responded similarly to increase of Cd concentration in solution. Cadmium concentration in roots and shoots increased significantly (P less-than-or-equal-to 0.05) with Cd application, but due to concomitant decrease in growth the Cd content of plants remained constant at solution Cd concentrations of 5 mum or above. We concluded that seedlings of durum cultivars with different growth potential responded similarly to Cd application in nutrient solution.