Mutagenicity of Oil Drilling Fluid (Potassium Chromate) on the Seedlings of Vigna unguiculata L. (Walp). in the Niger Delta, Nigeria

The morphological, leaf epidermal and anatomical distortions caused by the exposure of Vigna unguiculata L. to potassium chromate was investigated using 1-4%w/w of an oil field chemical Potassium chromate and Control (0). Results showed that 2-4%w/w concentrations elicited noticeable effects on the plant. Variations occurred in plant height, leaf area, number of leaves between the treated and the control plants. V. unguiculata treated with 1%w/w concentration had malformed and chlorotic leaves. The treated plant had reduced stomatal indices in both epidermal surfaces: adaxial (18.3%) and abaxial (66.3%) as against (26.3%) and (75.3%) observed in the control. The mid rib of the treated plants had thicker cuticle than the control plant. There were 6 layers of collenchymatous cells in the mid rib of the treated plant as against 5 layers of collenchymatous cells in the control. The petiole of the treated plant also had thick sclerenchyma cells around the vascular bundle while the sclerenchymatous cells around the vascular bundles in the control plant were thin. Oxalate crystals were seen in the parenchyma cells of both the treated and the control plants but more of the crystals were observed in the treated plants. Obviously some mutagenic effects were elicited on the test organism indicating that the oil field chemical should be excluded where this plant is grown so as to avoid losses or other adverse consequences of potassium chromate on V. unguiculata.