Alyssum montanum subsp. gmelinii, a rare plant species from coastal sand dunes, as a potential Ni accumulator: comparison with Alyssum murale

Plants from a separated population of Alyssum montanum subsp. gmelinii with a coastal-specific distribution on dune habitats of the Eastern Baltic Sea in territory of Lithuania and Latvia were used in the present study to assess Ni tolerance and its accumulation potential in comparison to a well-known Ni hyperaccumulator, Alyssum murale . A. montanum plants showed moderate tolerance to Ni, with pronounced negative effects on growth and physiological status from 0.5 g Ni L –1 . No A. montanum plants survived in 4 g L –1 Ni longer than for two weeks. In contrast, growth of A. murale was stimulated at 2 and 4 g L –1 Ni. Cultivation in presence of increasing concentration of Ni in substrate resulted in a linear increase of Ni concentration in leaf and stem tissues of both species. Leaves of A. montanum accumulated up to 0.626 g kg –1 Ni, compared to 21.976 g kg –1 in leaves of A. murale . Accumulation capacity of Ni in roots was less pronounced, with a clear saturation effect for both species. Ni treatment induced changes in concentration of different mineral nutrients and nonessential elements. Among the most pronounced stimulative effects, Co concentration increased in leaves and roots of both species, Cd concentration in leaves of both species, Cu concentration increased in stems of both species, and Fe concentration in stems of both species. It is concluded that the accession of A. montanum subsp. gmeliniii from coastal sand dunes of the Baltic Sea has good tolerance to increased substrate Ni concentration and exceptional Ni accumulation potential.