Assessment of phytotoxicity bioassay and metal accumulation potential of Ricinus communis L. genotypes during cultivation in iron mine soil of Jharkhand, India

Abstract

ABSTRACTS Seed germination and early seedling growth are crucial characteristics for determining a plant species ability to survive in stressed soil including mine soil (MS). In the present study, four genotypes of castor bean (Ricinus communis L.) an industrially important bioenergy crop, were grown in iron MS with different treatments of garden soil (GS) (0%, 25%, 50%, 75%, and 100%) to examine germination, growth indices (tolerance index (TI), seedling vigor index (SVI)) and metal accumulation potential. The study recorded significantly high germination, growth and biomass in 75% GS treatments and for the cultivar MSC-55. The TI was highest in 75% GS treatments for all genotypes, with no significant difference. The metal accumulation potential of castor was evaluated for Fe, Pb, Cu and Ni, all of which were detected in high concentration in iron MS. The translocation factors (TF) for Fe and Ni were recorded <1 for all genotypes which imply metals are stabilized in the castor roots, although for Cu and Pb it was found >1. The bioaccumulation factor was recorded highest for Fe (1.224–7.433) and Pb (0.846–9.056) for all genotypes. Furthermore, the root accumulation of Fe, Pb and Ni was observed highest with 8039.20, 177.70 and 88.10 mg kg−1, respectively. The metal extraction ratio (MER) for Fe and Pb showed the highest. Overall, the highest MER was recorded in order of MSC-55 > Leetos > Swati-1515 > Sai-33. The finding of the study indicates that the genotypes MSC-55 followed by Leetos can grow in MS and accumulate multiple metals in their root and shoots and can be employed as phytostabilizers and phytoextractors.