Growth responses of indian mustard [Brassica juncea (L.) Czern.] and its phytoextraction of lead from a contaminated soil

Indian mustard seedlings were grown in lead-contaminated soil, and growth responses and Pb uptake were examined. Lead was supplied to the growth medium as aqueous solutions of Pb nitrate at concentrations of 0, 100, 250, and 500 mu g Pb/ml. Results showed that, compared to control plants, total leaf area was reduced 25 and 47%, respectively, in plants treated with 250 and 500 mu g Pb/ml. The Pb-treated plants also exhibited anthocyanin pigmentation or purplish coloration. Shoot growth, however, was not affected by Pb. Root growth of plants treated with 250 and 500 mu g Pb/ml was reduced 21 and 44%, respectively, compared to untreated plants. Generally, the amount of accumulated Pb in shoots and roots increased with increasing concentration of applied Pb. When averaged across treatments, accumulation of Pb in roots was almost ten-fold higher than in shoots. While Indian mustard exhibited phytoextracting ability, further study is needed to enhance the effectiveness of its use for phytoremediation.