| Popis: |
The present study investigates the chromium (VI) induced phytoxicity and accumulation in the black gram (Vigna mungo L. cv. BVN-3) grown under refined sand pot culture. The phytotoxicity assessed with reference to growth behavior, water transport, metabolic alteration, yield, uptake and translocation of S, P, Fe and Cr under chromium (VI) stress. The black gram plants were treated with varied chromium (VI) at 0.00, 0.05, 0.10 and 0.25 mM concentration. After 5 d of Cr (VI) treatment, the foliar toxicity symptoms showed as loss of turgor and chlorosis of older leaves which also reflect in middle aged leaves later on at higher concentration of chromium (0.25 mM). At the later stage, chlorosis symptoms became critical and distorted to necrosis in patches with tapered lamina, thin tendrils and loosed coiling property. Cr (VI) induced toxicity observed on black gram as decreased growth and yield, impairment in photosynthesis activity, inhibition of metabolic and enzymatic activities and nutrient imbalances. Excess (0.25 mM) of Cr (VI) also caused a reduction in uptake and accumulation of iron in the leaves as compared to control (from 426.2 to 198.7 µg g-1 dw) with more uptake and accumulation of sulphur and phosphorus. Higher accumulation of Cr was recorded in the leaves (166.5 µg g-1 dw) followed by roots (123.4 µg g-1 dw) and stems (46.6 µg g-1 dw) at 0.25 mM after 29 d of treatment. Therefore, consumption of Cr containing black gram may have human health concern due to toxic Cr accumulation and nutrition imbalances. |
