ABSTRACT
A pot culture experiment was conducted to study the effect of biomass power plant effluent on seed germination, seedling growth and chlorophyll content of green gram (variety LGG 460) have been estimated at different effluent concentrations and time intervals. The effluent is alkaline in nature (pH 8.5), odorless, and comprises of heavy metals such as Cr (0.071 mg l-1),Cu (0.014 mg l-1), Mn (0.036 mg l-1), Fe (0.05 mg l-1),Co (0.31 mg l-1), Ni (0.041 mg l-1),Cd (0.028 mg l-1), Pb (0.108 mg l-1) and Zn (6.73 mg l-1). The germination percentage of seed, seedling growth and chlorophyll content showed a gradual decline with increase in effluent concentration. It has been observed that at 25% effluent concentration, there is growth in the root length (3.50 cm seedling-1), an increase in shoot length (23.90 cm seedling-1) and total chlorophyll content (4.467 mg g-1 fresh weight) up to 20 days. After 20th day there is decline in all the parameters observed. However, at higher concentrations of the effluent, toxic effects were observed from 20th day. This suggests that the effluent can be used safely for green gram cultivation, only after proper treatment and dilution.
ABSTRACT
The groundnut, Arachis hypogaea seedlings, when grown in pot cultures for 10–25 days at 25, 50, 100 "M CdCl2 , showed a marked decline in growth compared to control. Similar trend was observed for nitrate reductase (NR) and nitrite reductase (NiR) activities whereas proline, peroxidase (POD) and catalase (CAT) showed increasing trend when observed on the 10th day of the experiment. Changes have occurred in the physiological and biochemical activities which are observed even at low Cd levels (25 "M). At 100 "M concentration, with increase in experimental days, Cd has imposed drastic decrease in leaf and stem respectively, where nitrate reductase has varied from 20.87 – 79.41 and 29.11 – 72.91 % and nitrite reductase 21.66 – 79.41 and 43.58 – 75.92% respectively. Contrastingly Cd treated plant tissues showed an increase in proline 111.2 – 159.87 % (percentage changes) and 131.23 – 212.16 % for leaves and stems respectively, In addition cadmium caused significant changes in the activity of antioxidative enzymes, peroxidase 48.12 – 72.19 % in leaf and 37.71 – 75.25 % in stem and catalase 64.86 – 143.92 % in leaf and 129.13 – 214.74 % in stem as compared to control. The study concludes that the activities of NR, NiR, proline, POD, CAT are inhibited suggesting that Arachis hypogaea seedlings are under Cd stress affecting their growth.