Effects of polyamines (putrescine, spermidine and spermine) on root tip mitosis and chromosomes in Allium cepa L.

Abstract

In the present study effects of the polyamines; putrescine (Put), spermidine (Spd) and spermine (Spm) have been studied on root tip mitosis of Allium cepa L. Root tips of A. cepa were treated with a series of polyamine (PA) concentrations, ranging from 0.01, 1 and 2 mM for 3, 6, 12, 24 and 48 h. The roots were examined in permanent root tip squash preparations stained by the Feulgen technique. This research has confirmed that PAs have various effects on chromosomes. PA concentrations used, generally had a marked mitodepressive effect on mitotic index (MI) but at 6 h treatment of Spm, Spd and Put at all concentrations had increased MI. Polyamines affected the relative duration of each mitotic stage as compared to the control. They also increased frequency of abnormal mitosis. The types of abnormalities induced are: chromosome stickiness, c-metaphase, anaphase and telophase bridges, disturbed chromosomes of anaphase and telophase stages, lagging and forward chromosomes at anaphase and telophase. Binucleate cells and micronuclei formation at interphase cells were also observed. © 2005 The Japan Mendel Society.