Within and between population genetic variation for zinc accumulation in Arabidopsis halleri

Hyperaccumulator plants in the field show significant variation in the metal concentration in their aerial parts, but little is known of the causes of this variation. This paper investigates the role of soil zinc (Zn) concentration and genetic variation in causing between and within population variation in Zn accumulation in Arabidopsis halleri.. Seed from 17 populations of A. halleri collected in central Europe were grown under standard conditions at three external Zn concentrations and tested for Zn concentration in the leaves. Between population variation was highest at low external zinc concentrations. At 10 muM Zn some plants had very low leaf Zn concentrations, and were indistinguishable from nonaccumulators. However, at higher Zn concentrations, all plants showed hyperaccumulation. There were no differences in the accumulating abilities of populations from sites with different degrees of contamination. Heritability of accumulation, determined for individual families from three populations, was quite high (25-50%), indicating that selection for increased accumulating ability should be possible, although selection would be easier at low external Zn concentrations. The Zn concentration of field collected plants was affected partly by plant genotype but not by the total soil Zn around their roots.