TOXIC EFFECT OF ARSENATE ON GERMINATION, EARLY GROWTH AND BIOACCUMULATION IN WHEAT (Triticum aestivum L.).

Damaging influence of arsenate(V) on germination and early growth of wheat (Triticum aestivum L.) was checked through pot bioassays. Four concentrations of As(V) i.e. 0.013, 0.025, 0.038 and 0.05 mg pot-1 were used to spike sandy loam soil (sand: 76%, silt: 15%, clay: 9%). Different As(V) treatments in the soil resulted in significant reduction in germination rate (G%), germination index (GI) and relative germination rate (RGR), while increased in arsenic response index (ARI). Shoot growth and biomass were significantly declined by 40-90%, and that of roots were decreased by 50-99% in 2-week and 4-weeks old plants. Morphological symptoms like yellowing of leaf margins, stunt roots and stems were observed at higher dose (0.05 mg) of As(V) in 4-week seedling. The tolerance index (Tindex) of seedling was decreased and metal accumulation was increased that revealed increase in the seedling sensitivity with increasing concentrations of As(V). Root accumulated more metal than the shoots. It was concluded that As(V) has potential to drastically reduce seed and seedling growth of wheat by accumulating in plant tissues, therefore it is required to assess uptake by plants growing in arsenic contaminated areas to address food security challenging in Pakistan. [ABSTRACT FROM AUTHOR]