Phytotoxizität von Thallium (Tl) in Hydrokultur Teil 1: Einfluß von Tl(I) auf das Wachstum und die Schwermetallgehalte von Erbsen- und Ackerbohnenpflanzen

Phytotoxicity of Thallium (Tl) in Culture Solution Part 1: Effects of Tl(I) on the Growth and Heavy Metal Contents of Pea and Field Bean Plants The effects of TlNO₃ and Tl(I)EDTA on growth and heavy metal contents of pea plants (Pisum sativum L. cv. Aromata) and field bean plants (Vicia faba L. cv. Hangdown) were compared in hydroponic culture experiments. In the presence of TlNO₃, the essential heavy metals were available to the plants in their ionic forms. When Tl(I)EDTA was present the essential heavy metals were available as chelated complexes. TIN03 content of each organ was increased. The highest TI content was found within the stems. The increased TI contents were accompanied by depressed Mn, Zn, and Cu contents of the roots and depressed Mn contents of the stems, but increased Fe contents of the stems. Substitution of TIN03 by TI(1)EDTA resulted in a stronger growth inhibition of the pea plants, and higher TI contents of each organ. The highest TI content was found within the stems. TI(1)EDTA depressed Mn in the roots, but increased Fe and Mn in the stems, and Fe, Zn and Cu in the leaves. The increases may due to concentration by growth inhibition. The growth of the field bean was not effected by TIN03 nor by TI(1)EDTA. The field bean contained most of the TI within the roots and translocated only relatively small amounts to the shoots. This pattern was independent of the TI compound. Increasing concentrations of TIN03 resulted in depressed Mn and Zn contents of the roots, and Mn contents of the stems. Chelation of Tl(1) resulted in a decrease of the TI content of each organ. TI(1)EDTA depressed only the Mn content of the roots.