Phytotoxic Effects of some Antibiotics

Abstract

The toxicity of a number of antibiotics, coumarin, and 3-indolylacetic acid to wheat, clover, and mustard seedlings has been assessed by a simple germination test. The percentage germination of wheat was not markedly affected by any of the compounds tested although root growth was reduced. Severe inhibition of root growth of the other seeds was usually accompanied by reduction in percentage germination. None of the antibiotics tested were as inhibitory as indolylacetic acid, but most were more toxic than coumarin. The more toxic of the antibiotics were alternaric acid, glutinosin, mycophenolic acid, and gliotoxin. The least toxic were griseofulvin, penicillin, and streptomycin. Higher concentrations of the latter antibiotic were found to have an inhibiting effect on the synthesis of chlorophyll.