Impacts of cadmium toxicity on seed germination and seedling growth of Triticum durum cultivars

Abstract

Heavy metal (HM) pollution is a threat to ecosystem balance and food security. Cadmium (Cd) is particularly hazardous to humans and accumulates in agricultural soils due to industrial activities and natural sources. Even if Cd adversely affects plant growth and vital functions, few studies have investigated its effects on durum wheat, an important staple crop. Therefore, this study aimed to understand the morphological alteration induced by Cd during the germination phase of durum wheat (Triticum durum L.) seeds to evaluate the tolerance of three cultivars (Karim, Nachit, and Louiza) to Cd stress. The experiment involved germinating wheat seeds in nine concentrations of Cd (0, 0.125, 0.25, 0.375, 0.5, 0.675, 0.75, 0.875, 1 g/L) where germination rate, biomass production, shoot and root length, vigor index, growth inhibition, and tolerance indices were assessed. The different treatments were arranged using a completely randomized design. The results showed that Cd negatively affected wheat germination. The minimum effect of Cd on germination percentage was recorded at 0.125 g/L of Cd for Nachit and Louiza, and at 0.25 g/L of Cd for Karim, while the maximum inhibition was noticed starting at 0.625, 0.875, and 0.625 g/L of Cd for Karim, Nachit, and Louiza, respectively. The negative effect of Cd on shoot and root length was more pronounced during seedling development than during germination. Cd had a greater effect on root length than on shoot length, with Louiza being the most affected cultivar. However, Cd had no significant effect on fresh and dry weight. Our research reveals that the presence of Cd pollution has a substantial impact on the initial growth stages of durum wheat with differential responses of the studied cultivars when exposed to Cd stress. These alterations in seedlings’ performances strongly emphasize the importance of evaluating Cd’s effects on plant development and fitness. This underscores the significance of this aspect not only for ensuring the health of our crops but also for safeguarding food quality in the presence of HM pollution.