Among the toxic elements release in the environment, mercury is considered
highly toxic to the growth of plants. The present studies report the effects of different
concentrations (1, 3, 5 and 7 mM) of mercury on seed germination and seedling growth
performance of mungbea (
Vigna radiata
) as compared to control. Mercury treatment in the
form of mercuric chloride at 1 mM did not show significant reduction in seed germination of
V.
radiata as compared to control. Increase in concentration of mercury to 3 mM produced
significant (p<0.05) reduction in seed germination. Mercury treatment at 7 mM-produced
significant (p<0.05) reduction in seedling and root length of the plants. The increase in
concentration of mercury treatment at 7 mM was found sufficient to cause significant reductions
in seedling dry weight of as compared to control. Mercury treatment at all concentrations
decreased seed germination, shoot, and root length and seedling dry weight. Increase in
mercury concentration upto 7 mM showed highest percentage of decrease in seed germination
(42%), seedling length (70%), root length (66%) and seedling dry weight (47%) of mungbean as
relation to control.
V. radiata were more sensitive to mercury stress in seedling growth and root
elongation than seed germination. The seedlings of
V. radiata showed greater tolerance to
mercury at 1 mM (85.83 %) and lowest at 7 mM (34.13%). These results show that there is a
negative effect towards germination and growth of mungbean by mercury treatment. Minimum
use of the mercury containing compounds in fungicide, pesticide and nematicide is
recommended. Special care should be taken to monitor the toxic pollutants available in the
immediate environment. The accumulation of such types of toxic pollutants in larger
concentrations by crop can produce harmful effects to crops and ecosystem as well.
