Effect of Trifluralin on Mitosis

Abstract

The compound α,α,α-trifluoro-2,6-dinitro- N,N -dipropyl- p -toluidine (trifluralin) inhibited mitosis in onion (Allium cepa L. ‘Yellow Globe’) and wheat (Triticum aestivum L. Thorn’) root tips. Photomicrographs showed that trifluralin affected mitosis in the same manner as colchicine. Arrested metaphases, c-pairs, micronuclei, amoeboid nuclei, and polyploidy were observed at various times after treatment. An increase in the percentage of arrested metaphases and a decrease in anaphase and telophase figures after 3 hr showed that mitosis was being blocked at metaphase. Prophase did not appear to be affected. Centrifugation of treated root tips displaced the chromosomes of arrested metaphases indicating that the spindle apparatus was disrupted.