Chromium translocation, concentration and its phytotoxic impacts in in vivo grown seedlings of Sesbania sesban L. Merrill.

Abstract

The present in vivo pot culture study showed hexavalent chromium (Cr+6) induced phytotoxic impacts and its translocation potential in 21 days old sesban (Sesbania sesban L. Merrill.) seedlings. Cr+6 showed significant growth retardation in 21 days old sesban (Sesbania sesban L. Merrill.) seedlings. Germination of seeds at 10,000 mg L-1 of Cr+6 exhibit 80% inhibition in germination. Seedling survival was 67% after 7 days of seedling exposure to 300 mg kg-1 of Cr+6. Shoot phytotoxicity was enhanced from 6% to 31% with elevated supply of Cr+6 from 10 mg kg-1 to 300 mg kg-1. Elevated supply of Cr+6 exhibited increasing and decreasing trends in % phytotoxicity and seedling tolerance index, respectively. Elevated supply of chromium showed decreased chlorophyll and catalase activities. Peroxidase activities in roots and leaves were significantly higher at increased supply of Cr+6. Cr bioconcentration in roots was nearly 10 times more than stems whereas leaves showed nearly double accumulation than stems. Tissue specific chromium bioaccumulation showed 53 and 12 times more in roots and shoots respectively at 300 mg kg-1 Cr+6 than control. The present study reveals potential of sesban for effective Cr translocation from roots to shoots as evident from their translocation factor and Total Accumulation Rate values.