Evaluation of bilge water-induced plant genotoxicity using randomly amplified polymorphic dna (rapd)

Abstract

Indiscriminate disposal of bilge water into water bodies has been identified as a source of environmental pollution. There is currently no study on the genotoxicity evaluation of bilge water using molecular maker. Physicochemical analysis of the wastewater showed that it was slightly acidic with a pH of 6.09 and contained nitrates, phosphates, chlorides, iron and nickel at amounts higher than the national (NESREA) and international (USEPA) maximum limits allowed for effluent discharge. The Random Amplified Polymorphic DNA (RAPD) technique was employed to evaluate the level of DNA alteration in Allium cepa root tips exposed to different concentrations of bilge water (1, 5, 10, 25 and 50%). Compared to the control, DNA polymorphism which was reflected by changes in the RAPD profiles as variation in band intensity, disappearance of bands and appearance of new bands, was induced by the different concentrations of bilge water on the genome of Allium cepa root cells. The genetic distances shown on the dendrogram revealed that the genotoxicity of the wastewater was concentration-dependent. This study has shown that polymorphism detected by RAPD can be considered as a powerful molecular marker assay for the detection of the genotoxic effect of bilge water.

 Keywords: Bilge water, RAPD, DNA damage, Allium cepa, Ships