The adaptive evolution of serpentine tolerance in selected species of Czech serpentine plants

Serpentine soils produce speciafic habitats with extreme edaphic conditions. which are hostile to plant life. They contain high concentrations of nickel and have an unfavorable calcium/magnesium ratio. The effects of Ni and Mg, two factors involved in the infertility of serpentine soils, were studied in Knautia arvensis, Silene vulgaris and Galium pumilum agg. Seedlings from serpentine and non-serpentine populations of three plant groups were grown in solutions with elevated concentrations of Ni, Mg and Ni+Mg. The total root growth, the growth of the tap-root, the number of lateral roots and growth of the longest leaf of plants was measured and compared among serpentine and non-serpentine populations. The serpentine populations showed generally higher tolerance to Ni and Mg stress than non-serpentine populations (suggesting possible adaptive origin of serpentine tolerance in the studied plant groups)