The Differential Response of Meristems of Vicia Faba to Colchicine

SUMMARY

The response of primordia and lateral root meristems to short treatments with colchicine (2–3 hours) is described. Evidence is presented that anaphase continues to occur in large primordia after it has been suppressed in lateral roots. Since the anaphases occur together with c-metaphases and restitution nuclei it is clear that colchicine reaches the primordia. The differential response of large primordia to colchicine is also demonstrated by the extent of other changes: accumulation of metaphases, prophase: metaphase ratios and M.I. The response of primordia and lateral roots to 0.05, 0.025, 0.0125 and 0.001% colchicine is compared and additional evidence is presented that large primordia show a differential response.