Effect of copper on growth and chlorophyll content of some herbs

The effect of heavy metals on growth and leaf chlorophyll content of three herbs originating from tolerant and sensitive populations was studied. Seeds of the Agrostis stolonifera L., Melandrium rubrum L. and Rumex acetosela L. were collected from the region with contaminated (tolerant population) and not-contaminated (sensitive population) soils. Seedlings of the above mentioned herbs were treated with different Cu concentrations and cultivated under laboratory conditions. Leaf chlorophyll content was determined in Agrostis stolonifera L. plants (tolerant and sensitive populations) cultivated in growth chamber before and after Cu application. The plants of both tolerant and sensitive populations accumulated higher Cu content in the leaves and roots. However, higher Cu content was in the roots than in the leaves as well as in the seedlings of tolerant than sensitive populations. Growth of the roots and shoots was reduced, but the first one was reduced faster. The index of tolerance (IT) was higher for the plants of tolerant population as the result of their adaptation to the higher metal content in the soil. The chlorophyll content was lower in Cu affected leaves of tolerant and sensitive populations. On the basis of plant adaptation to high metal content in the soil, these plants could grow, reproduce and cover anthropic substrates. Thus the tolerant plant populations could help to solve the problem concerning with recultivation of contaminated and degraded soils.