Cadmium accumulation, translocation, and assessment of eighteen Linum usitatissimum L. cultivars growing in heavy metal contaminated soil

Flax (Linum usitatissimum L.) is suitable for growing in heavy metal polluted soil for non-food purposes and can be used as potential crops for cleaning the soil from heavy metals. The main objective of this study was to investigate flax/linseed phytoextraction of cadmium (Cd), including uptake, translocation, and accumulation differences in organs among flax/linseed cultivars. A field experiment was carried out in Cd contaminated field of Chinese southern area with nine flax, one dual-purpose, and eight linseed cultivars. Cd concentrations in plant organs (root, xylem, phloem, and capsule) and biomass of different organs of each cultivar were measured and evaluated. Significant differences in Cd concentration and accumulation among organs were observed. The most Cd was accumulated by phloem, which was 2 ∼ 4 times more than other organs, followed by roots, xylems and capsules played a comparably smaller role. The uptake of Cd by flax/linseed from per hectare was calculated and had highly significant positive correlation with biomass. Phloem accumulated 45 ∼ 55% of total Cd from the soil by the plant. Among testing 18 flax/linseed cultivars, one flax cultivar (Zhongya 1), and two linseed cultivars (Y2I329 and Y2I330), which extracted more than 60 g ha-1, can be considered as Cd accumulators for phytoremediation of Cd contaminated soil.