Evaluation of Morphological and Biochemical Changes in Bellis perennis under Lead-Contaminated Soils

Heavy metals, as a limiting factor, affect plant physiological characteristics. Heavy metals toxicity leads to poor seed germination and limited plant growth. The effect of heavy metal lead (Pb) at six concentrations was investigated on morphological and biochemical traits of Bellis perennis in a completely randomized design experiment with five replications. Also, the ability of lead absorption by B. perennis was evaluated. The results showed that at higher concentrations of Pb, the percentage and rate of seed germination were decreased. Other traits such as root and shoot dry weights decreased significantly with increased lead concentrations by 70% and 23%, respectively. Total chlorophyll a + b decreased as Pb concentration was increased (66%). Proline accumulation and activity of catalase and ascorbate peroxidase enzymes increased significantly at higher concentrations of Pb by 30%, 42%, and 42%, respectively. Based on the changes in some plant traits such as enrichment coefficient, phytoextraction potential, and tolerance index, it can be concluded that B. perennis might have a high potential for phytoremediation, and also lead metal refining ability. It was observed that the Pb application did not prevent seed germination of B. perennis, but increasing concentrations disrupted some seed germination traits. Bellis perennis showed good tolerance at low concentrations of Pb, while at higher concentrations, the tolerance index decreased by about 60%, suggesting an acceptable tolerance at high concentrations. Significant accumulation of Pb in the roots of B. perennis indicated it is a suitable plant for phytoremediation in lead-contaminated environments.