Accumulation of potentially toxic elements by plants of North Caucasian Alyssum species and their molecular phylogenetic analysis.

Abstract

Accumulations of potentially toxic metals were investigated in soils and five North Caucasian Alyssum species from metalliferous areas and non-metalliferous areas in Karachay-Cherkessia, Kabardino-Balkaria, Dagestan and the Krasnodar region. Analyses of field samples showed that chemical features of the soils significantly affected the concentrations of Ni, Co, Zn, but had less effect on Cu and Pb concentrations in the shoots of Alyssum. Variations in the degree of accumulating ability were found in the studied species, including hyperaccumulation of Ni in Alyssum murale (up to 12,100mgkg-1), and significant accumulation of Zn in A. gehamense (up to 1700mgkg-1). A comparative molecular genetic analysis of two A. murale populations, both Ni-hyperaccumulating population from Karachay-Cherkessia and non-hyperaccumulating population from Dagestan, indicated considerable genetic difference between them. This result supports the hypothesis that the selection of metal hyperaccumulator species with enhanced phytoremediation efficiency should be considered at the population level.