SOIL GENOTOXICITY BIOMONITORING IN RECULTIVATED FACTORY AREA USING THE CYTOGENETIC AND MOLECULAR ASSAYS IN TWO PLANT TEST-SYSTEMS

Abstract

Soil pollution with industrial leftovers is of real danger to living organisms since harmful effects can arise after exposure to the contaminants in the soil. In our study, we applied a plant bioassay battery to monitor soil genotoxicity after short-term exposure to the soil. The soil was collected in 3 rounds: at the central part of the brownfield before (S-I) and after (S-III) topsoil removal, and at the brownfield periphery (S-II). The permissible value of the total contamination index is <16 and the corresponding values were 780 in S-I, 69 in S-II and 133 in S-III soil showing that whole brownfield territory is extremely polluted with heavy metals. Cytogenetic markers were recorded in Allium and Tradescantia test-systems and two types of molecular markers, RAPD and ISSR, were analysed in Allium. Our results revealed that the most polluted soil sample has induced an alarming increase of apoptotic cells in onion roots. Chromosome aberration and micronuclei frequency in Allium decreased inconsistently along with the pollution reduction in the soil. Increased frequencies of all cytogenetic markers were revealed in Tradescantia cuttings after exposure to the S-I soil extracts. Cluster analysis of Allium RAPD and ISSR markers showed that the most polluted soil samples induced genetic changes in onions different from those induced by the least polluted soil. Both plant test-systems in this study confirm that soil from the brownfield is harmful to plants and is potentially hazardous to humans.