Exploring Phytoremediation Potential of Vigna radiata & Vigna aconitifolia Under Hexavalent Chromium Induced Stress in Hydroponics

Abstract

A global concern regarding environmental pollution with chromium contamination of agricultural soil has set up a critical challenge as its accumulation is noxious. Toxicity of Chromium to plants depends on the valence state where hexavalent chromium; Cr(VI) is considered highly toxic. Therefore, present study investigates the phytoremediation potential of leguminous plants; Vigna radiata and Vigna aconitifolia for the reduction of Cr (VI) hydroponically. The study was designed by growing the two plants in varying concentration of chromium ranging from 100 mg kg^-1 to 800 mg kg-¹ and parameters were assessed for toxicity and remediation potential under hexavalent chromium stress. V. radiata as compared to V. aconitifolia showed a significant decrease in root and shoot lengths with increasing concentration with 17.31% & 78.85% and shoot length 26.39% & 72.22% in V. radiata at 100 mg kg-1 and 800 mg kg-1 respectively. Whereas; in V. aconitifolia it was found to be as 9.26% & 72.22% in root, 18.67% & 68% in shoot at 100 mg kg-1 and 800 mg kg-1 respectively at p<0.05. Translocation factor > 1 was observed in both the plants with maximum as 2 in V. aconitifolia at 600 mg kg-1 and maximum remediation percentage of 85.33% which makes it a better phytoremediator than V. radiata. Certain morphological aberrations such as necrosis of leaves and discoloration of roots and shoots were observed at 600 mg kg-¹ and 800 mg kg-¹ concentration of chromium. Therefore based on these observations V. aconitifolia can be considered as a potential phytoremediator and hyperaccumulator of Cr(VI) over V. radiata.