MITIGATION OF ARSENIC TOXICITY IN WHEAT WITH SODIUM NITROPRUSSIDE (SNP)

Abstract

The arsenic (As) contamination is increasing gradually in agricultural land with climate change. Wheat is the second cereals after rice in Bangladesh. Therefore, wheat production is affecting with As contamination. A pot experiment was conducted in the farm of Sher-e-Bangla Agricultural University, Dhaka, during rabi season, November 2015 to March 2016 to examine the role of sodium nitroprusside (SNP) as NO donor on mitigation of As toxicity in wheat. In this experiment, the treatment consisted of four different As levels viz. As0 = without As (control), As1 = 30 mg As kg-1 soil, As2 = 60 mg As kg-1 soil, As3 = 90 mg As kg-1 soil and three different concentrations of SNP viz. N0 = 0 mM SNP, N1= 0.1 mM SNP and N2 = 0.2 mM SNP. The experiment was laid out in two factors Completely Randomize Design (CRD) with four replications. The total treatment combinations were 12 (4x3). Results of the experiment showed a significant variation among the treatments in respect of most of the parameters as morphological, physiological, yield contributors and yield characters. The higher levels of As showed greater reduction of growth, development and yield component to control or without As. Separately, exogenous application of SNP improved the morpho-physiology, yield contributing characters and yield of wheat. The different parameters such as plant height, leaf number plant-1, number of tiller and effective tiller plant-1, length of spike, membrane stability, number of spikelet spike-1, number of effective spikelet spike-1 number of grains plant-1, 100 grains weight and grain yield pot-1 of wheat significantly decreased with As contamination whereas SNP significantly increased these grain yield pot-1 by improving the morphological, physiological and yield characters. The interaction between different levels of As and SNP showed significant difference in wheat by altering the morpho-physiological and yield contributing characters and grain yield per pot. The maximum grain yield (12.60 g pot-1) was obtained from 0.1 mM SNP along without As (As0N1) treatment combination which did not show any difference with 30 mg As kg-1 soil and 0.1 mM SNP (As1N1). The grain yield pot-1 of wheat was improved from 10.30 g to 12.35 g, 8.50 g to 9.82 g and 5.69 g to 6.88 g at 30 mg, 60 mg and 90 mg As kg-1 soil, respectively along with 0.1 mM SNP and are suggesting that exogenous foliar application of SNP mitigates the adverse effects of As toxicity in wheat.