Effects of cadmium, copper, and zinc on germination and post-germination growth of chia seeds

In recentyears, concerns regarding environmental pollution and its impact on agricultural production have intensified due to the ongoing dispersal of heavy metals. This study investigated the ecotoxicological effects of three heavy metals (cadmium (Cd), copper (Cu), and zinc (Zn)) on the germination and post-germination growth of chia (Salvia hispanica). Except for the notable 18.2% decrease in germination rate with Zn treatment on the first day, the germination rates of metallic-stressed chia seeds did not significantly differ from the control for the other metals. However, the parameters related to post-germination growth were negatively impacted in varied ways by the metal treatments, causing a significant hindrance in radicle elongation (ranging from 56.3% to 81.6%) and hypocotyl elongation (from 27.1% to 76.5%), as well as a notable decrease in both fresh and dry biomasses. The most significant reduction in radicle and hypocotyl elongation occurred with Zn and Cd treatment. The largest decrease in fresh and dry biomass was seen in the radicle and hypocotyl under Zn exposure. The tolerance index demonstrated that chia showed the greatest ecotoxicological tolerance to Cu, followed by Cd and Zn. This suggests that chia has potential for cultivation in polluted areas, particularly those contaminated with Cu.