Effect of chromium (VI) on wheat seedlings and the role of chelating agents

Toxic effect of chromium concentration with and without chelating agents was studied on wheat seedlings grown hydroponically. Graded dry wheat seeds (Triticum aestivum L.C.V., UP 262) obtained from Odisha University of Agriculture and Technology, Bhubaneswar were sterilized and germinated under controlled condition at 25 degrees C in darkness for two days. The seedlings were grown in growth chamber with 7 h/16 h light and dark period with a photon flux density of 52 mu eM(-2) S-1. The growth parameters, i.e. root and shoot length, and fresh and dry matter of 5-7-day-old seedlings were determined. Different chromium concentrations (5-100 mu M) with chelating agents (EDTA, citric acid, ZnSO4; 50 mu M) were used during growth. Biochemical analysis of chlorophyll content was made from 7-day-old primary leaves of seedlings grown in different Cr (VI) concentrations with or without chelating agents using spade meter. Cr (VI) contents in root and shoot were analysed on hydroponically grown 7-day-old seedlings with the help of AAS. The study showed overall growth retardation of wheat seedlings with increase in Cr (VI) concentration. However, lower concentration of Cr (VI) was found to be stimulating chlorophyll biosynthesis in wheat plants.