Agro-morphological changes caused by the accumulation of lead in Corchorus olitorius, a leafy vegetable with phytoremediation properties

Lead (Pb) can enter the food chain through the consumption of contaminated plants and can cause serious health issues. However, research on how Pb accumulation affects morphology of leafy vegetables in South Africa is minimal. This study tested the effect of lead accumulation on vegetative and reproductive traits of Corchorus olitorius. Plants were grown under varying Pb concentrations, and studied for their variation in vegetative and reproductive traits as well as Pb accumulation in leaves, stems and roots. Plants grown within allowable soil concentrations of 150 mg kg–1 Pb accumulated toxic (≥ 10 mg kg–1) Pb in all plant parts without causing any morphological defect, except for a decrease in chlorophyll content. Minor reductions in growth and yield were evident only at 900-1000 mg kg–1 concentration. Pb accumulation increased as its concentration increased in the soil, with a higher accumulation in roots in comparison to aerial parts. In conclusion, C. olitorius can grow and reproduce under toxic Pb levels (≥ 300 mg kg–1) and accumulate toxic amounts of Pb (≥ 10 mg kg–1) without visible morphological defects. Therefore, it is suitable for phytoremediation but unsafe for consumption when it is collected from sites prone to Pb contamination.