Zilkah, S., Department of Plant Genetics, Weizmann Institute of Science, Rehovot, Israel
Bocion, P.F., Department of Plant Genetics, Weizmann Institute of Science, Rehovot, Israel
Gressel, J., Department of Plant Genetics, Weizmann Institute of Science, Rehovot, Israel

The effects of a broad range of compounds were assessed using both seedlings and callus cultures of five species. An experimentally justified ranking procedure was used to facilitate the comparison of the inhibitory characteristics at multiple concentrations. When the effects on seedlings of Lycopersicon esculentum, Solanum nigrum, Chrysanthemum segetum and Cirsium arvense were compared to those on white calli of the same species, some positive correlations were obtained; photosynthesis inhibitors affected seedlings much more than calli and some compounds affected calli much more than seedlings. Better correlations were obtained between the effects on Rumex obtusifolius seedlings and on green Rumex calli; the only exceptions being those compounds affecting mainly the calli. Thus callus cultures, especially green ones, have a potential for use to assess possible phytotoxicity as well as to detect potential toxicity of compounds not penetrating into or being translocated in whole plants. © 1977 Oxford University Press.