Bioassay as a tool for assessing susceptible and resistant plant species for field contaminated with industrial effluent

A bioassay technique was used to select plant species that were able to germinate and grow in a site contaminated with flash torch and battery manufacturing industrial effluents. Three varieties each of rice, namely Surya-52, Jaya-14 and Pant-10; three varieties of pulses [Gram (Bahar), Mung (K-851) and Lens (T-9)] and three varieties of oilseeds (Mustard-RS-30, Mustard-B-9 and Mustard T-69) were used for the determination of phytotoxicity by bioassay technique. The average % phytotoxicity for rice was 18.03% (14.34-22.7%), for pulses was 15.76% (8.75-26.64%) and for oil seed was 11.09% (6.42-15.24%). Accumulation of metals (Cu, Fe, Mn, Cd, Cr and Pb) was estimated in the root, shoot and edible parts of different crop varieties grown in pot culture up to maturity and treated with industrial effluent. The concentration of different metal ions in root, shoot and edible parts were in the range of Cu: 9.25-45.25, 7.25-42.35 and 5.65-35.26; Fe: 60.66-212.25, 45.24-155.62; Mn: 7.12-38.30, 6.25-27.27.23 and 4.25-24.45; Cd: 0.80-2.45, 0.75-2.12 and 0.45-1.95, Cr: 6.54-28.25, 5.36-24.45 and 4.35-16.32; and Pb: 0.95-3.75, 0.78-2.25 μg/g d.w. respectively. A higher concentration of Cd was found in Surya-52 rice variety and in Gram (Bahar) pulse variety and of Pb was detected in Surya-52 rice variety. Cd and Pb are non-essential metal ions and highly toxic to plants. Accumulation of toxic metal ions like Pb and Cd in the edible parts of oil a seed variety may not exceed the recommended daily intake limits. Percentage phytotoxicity and inhibition of root and shoot length was also less in the oil seed variety. Thus these plant varieties can be considered for cultivation in fields contaminated by waste from the flash-torch and battery-manufacturing industry.