CYTOLOGICAL EFFECTS OF PESTICIDES .9. EFFECTS OF THE PHOSPHONOTHIOATE INSECTICIDE LEPTOPHOS ON VICIA-FABA

The effects of the insecticide 0-4-brome-2, 5-dichloro-phenyl O-methyl phenylthiophosphonate “Leptophos” has been studied on: root-mitosis, seed-germination, root- and shoot-lengths of Vicia faba. Two types of treatments were conducted: seed-soak and root-treatments. Both treatments affected a significant percentage of abnormal mitoses. Seed-soak treatments for 48 and 72 hours affected marked inhibition of cell division. Disturbed prophases, meta- and anaphases (where the chromosomes spread irregularly in the cell) comprised the main type of the observed anomalies. Lagging chromosomes and chromosome fragmentation were also observed. Soaking the seeds in a saturated solution of Leptophos for 72 hours caused marked inhibition of root- and shoot-growth, which was attributed to the inhibition of cell division. © 1979, Japan Mendel Society, International Society of Cytology. All rights reserved.