Uptake of cadmium (Cd) by selected citrus rootstock cultivars

Abstract Cadmium (Cd) is a primary heavy metal causing crops toxicity, however, Cd uptake by citrus is little studied and largely unknown. In this study, nine (9) citrus rootstock cultivars were selected and grown under Cd stress at concentrations of 0, 2.5, 10, 20, 50, and 100 mg L−1 (Cd0, Cd2.5, Cd10, Cd20, Cd50 and Cd100, respectively) for 30 d, and citrus growth, Cd concentration, Cd transport ratio (TR%), and Cd uptake factor (PUF%) were measured. Results showed that after 30 d treatments, all selected citrus rootstocks remained alive under a relatively low Cd concentrations (Cd0, Cd2.5 and Cd10), but the mortality rate increased with increasing Cd concentrations beyond Cd20, and all citrus completely died at Cd100. Cd exposure significantly suppressed seedling growth. At 20 % growth reduction, tissue Cd concentrations were Cleopatra mandarin (C. reticulate Blanco)