A COMPARISON OF HERBICIDE BIOASSAYS IN CELL-CULTURES AND WHOLE PLANTS

Dose-response curves were established for the herbicides chlorsulfuron , metsulfuron-methyl, ethametsulfuron-methyl, imazamethabenz and glyph osate. The plant species were Daucus carota L. and Triticum aestivum L . in cell culture assays, and D. carota L., T. aestivum L., Stellaria media L., Chenopodium album L. and Avena sativa L. in whole plant assa ys. Potency ranking of herbicides were similar in the two assays. Low doses of herbicide stimulated growth in both assays, but stimulation w as greater in cell cultures. Image processing measured growth in cell cultures and was more sensitive to small differences in responses than manual counts of cell colonies. Dose-response curves had the same sha pe in both assays, but cell cultures were more sensitive than were who le plants.