DBPapers
DOI: 10.5593/SGEM2014/B61/S25.042

CHROMOSOMAL ABERRATIONS INDUCED BY PENTIMETHALIN IN ALLIUM SATIVUM ROOT MERISTEMS

Bonciu E., Iancu P., Soare M., Bonea D., O. Panita
Wednesday 1 October 2014 by Libadmin2014

References: 14th International Multidisciplinary Scientific GeoConference SGEM 2014, www.sgem.org, SGEM2014 Conference Proceedings, ISBN 978-619-7105-20-9 / ISSN 1314-2704, June 19-25, 2014, Book 6, Vol. 1, 301-308 pp

ABSTRACT
Garlic (Allium sativum) is an edible plant used as food and spice. In popular medicine it is considered, along with the onions, a real remedy due to the rich content of vitamins and minerals. Pentimethalin is the active component of the herbicide Stomp 330 EC; this is frequently used by the farmers to control weeds in the garlic cultures. Cytogenetic effects of Pentimethalin have been tested on the root tip cells of Allium sativum L., with a series of concentrations (1.5; 2 and 3 ppm), for 6, 12 and 24 hours. The control has been untreated. Garlic bulbs have been grown in water at room temperature (20 ± 2 °C); when the newly emerged roots are 2 cm in length, they are used in the test. Microscopic slides have been prepared by using Feulgen-Rossenbeck method for coloring the chromosomes and squash technique. The measurements were made under an optic microscope (two models have been used: MBL-2000 Kruss and Celestron 44340 LCD Digital) by considering 15 microscopically areas per slide. Two parameters were studied: the mitotic index and chromosomal abnormalities. The number of abnormal cells was counted in each phase of mitosis. The analysis of variance was used to assess the significant differences between control and each treatment. The results were analyzed using statistical program for Windows. The effects of increasing concentrations of Pentimethalin were: decrease in mitotic index and induction of a high level of chromosomal abnormalities. Thus, the mitotic index decreased with increasing the herbicide concentration at each exposure time; on the other hand, various chromosomal abnormalities like rings, fragments, bridges, stickiness, laggards and micronucleus were observed. From this point of view, the bridges were generally observed in all treatment alternatives. The frequencies of chromosomal abnormalities increase with increasing the herbicide concentration. In this regard, the differences among the concentrations have been significant, when compared with untreated control. Our study reveals a direct correlation between herbicide concentration, exposure time and mutagenic effects observed in exposed Allium sativum root cells. Cytologic effects of Pentimethalin to garlic, suggest prudence regarding abusive usage of this substance. However, supplementary studies are necessary to determine the molecular mechanisms whereby Pentimethalin induce genotoxic effects to plants. Besides, there are still many chemical substances for plant protection whose possible genotoxic effects are unknown.

Keywords: Garlic, Pentimethalin, mitotic index, chromosomal aberrations.