Cadmium accumulation in the grain of durum wheat is associated with salinity resistance degree

Abstract

A serious problem in durum wheat cultivation is its genetic capacity to accumulate cadmium (Cd) in the grain. The aim of the study was to verify if the degree of durum wheat resistance to NaCl salinity is related to its tolerance to Cd contamination, and to search for physiological markers of Cd accumulation in the grain. The experiment involved a salt sensitive cv. Tamaroi and a salt resistant line BC₅Nax₂, as well as a moderately salt tolerant line SMH87. The plants grew in the soil supplemented with 3 mg or 5 mg Cd/kg dry weight. The plant response to Cd was evaluated based on chlorophyll fluorescence (ChlF) and Cd content in the grains. Toxic effects of both Cd levels on photosynthetic performance index were the strongest in salt sensitive cv. Tamaroi, which showed the highest Cd content in the seeds. We therefore assumed that tolerance to salinity and Cd has a common physiological background, and that ChlF parameters may be used as the markers of Cd tolerance.