The effects of plant traits and phylogeny on soil-to-plant transfer of 99Tc

Assessments of the behaviour of 99Tc in terrestrial environments necessitate predicting soil-to-plant transfer. An experiment with 116 plant taxa showed that 99Tc transfer to plants was positively related to plant dry weight but negatively related to % dry matter and age at exposure. Activities of 99Tc analysed by hierarchical ANOVA coded with an angiosperm phylogeny revealed significant effects, with 55% of the variance between species explained at the Ordinal level and above. Monocots had significantly lower transfer of 99Tc than Eudicots, within which Caryophyllales > Solanales > Malvales > Brassicales > Asterales > Fabales. There was a significant phylogenetic signal in soil-to-plant transfer of 99Tc. This phylogenetic signal is used to suggest that, for example, a nominal Tc Transfer Factor of 5 could be adjusted to 2.3 for Monocots and 5.3 for Eudicots.