IN VITRO RELATIONSHIP BETWEEN CADMIUM STRESS AND THIOUREA IN TWO BARLEY GENOTYPES

Cadmium (cd) becomes very perilous pollutant for living things when its concentrations exceed certain threshold value. barley (hordeum vulgare l.) can accumulate high amount of cd but the genotypic differences in barley for cd uptake have not been clearly determined. the objective of this work was to determine the effects of three cd levels (0, 500, 1000 and 1500 μm/l) and alleviation of its toxicity by 0 and 10 mm thiourea (tu) on relative fresh and dry weights, macro- and micronutrients and antioxidants activation for scavenging reactive oxygen species in two barley genotypes cultured in vitro. one month old in vitro cultured two barley genotypes were done under controlled conditions and tu was applied with and without increased doses of cd. one month old calli were treated with cd alone and in combination with of tu. after 15 days of growth, the plants were harvested and the data on relative fresh weight were collected and then the other data were taken according to the procedures. the increased doses of cd significantly affected all the parameters and tu alleviates the cd stress to some extent. the results revealed that high cd toxicity is possibly associated with a decline in fresh and dry weight, macro and micronutrients and enhanced production of cat and sod but amelioration occurs by tu to some extent in both genotypes. however, jau-83 proved more tolerant than haider-91.