Evaluation of application of B. mycoides NR5 on alleviation As toxicity in Spinach (Spinacia oleracea L.)
The effect of arsenic (V) on spinach plant was studied using pot experiment. Sandy loam textured soil was collected from non-contaminated fields, air dried, sieved through a 2mm mesh, homogenized and a total of 3.0 kg of air-dried sterilized soil was placed in each pot. As 25mg Kg-1 supplied in the form of Sodium arsenate  dibasic heptahydrate (Na2HAsO4.7H2O) was mixed with soil and kept for a week to stabilize the mixture. Plants without arsenic served as control. Pot experiment was performed in Completely Randomized Design (CRD) in three replicates. Seeds of spinach (Spinacia oleracea L.) var . F1-MULAYAM were disinfected with 1% sodium hypochlorite solution, washed with deionized water three times to completely remove disinfectant and then placed in Petri dishes inside the folds of wet filter papers at 25±1ºC for germinated. Four days later germinated seeds were withdrawal from wet paper towel and coated with 1% carboxy methyl cellulose (CMC) and air dried. Five coated seeds were placed in each pot and a control, and marked properly. This experiment was carried out in controlled conditions. The position of pots was changed on a regular basis to ensure similar light and temperature exposure. The plants were irrigated with deionized water (100 mL) twice per day and one set (from each concentration) of pot harvested after maturation at 45, 60, and 75 days after inoculation. The plants were washed with tap water and then deionized water and were cut down into shoots and roots. Fresh weights as well as length and shoot diameters and other physical appearance were recorded. Roots and shoots were oven dried at 70 ºC for 48 h, powdered and sieved through 2 mm mesh size.