Effect of Insecticide Imidacloprid on the Dividing Cells of Root Meristem of allium Cepal.

Abstract

Imidaclolprid is a systematic, chloro-nicotinyl insecticide with soil, seedand foliar uses for the control of sucking insects including rice hoppers,aphids, whiteflies, termites, turf, soil insects and some beetles.In presentwork the cytological effects of insecticide Imidacloprid on rootmeristematics cells of Allium cepa L. were studied. The differentconcentration of insecticide i.e.25%, 50%, 75% and100% were treated indifferent time periods i.e. 3,6,12, and 24 hours separately.The observation data was used tocalculate the chi-square value and wasrecorded as 3.3 indicating less effectiveness of the chemical. The mitoticindex value of treated meristem was higher than control at differentconcentration in all cased expcept some interruption in some periodictreatment. This increased in mitotic index reveals mitoactivative action ofthe insecticide Imidacloprid. Among the phase Indic, the prophase indexis generally higher which increase as the concentration and time periodincreases. Increase in prophase index show prophase poisoning i.e.inhibits further division.Besides such activities this chemical also shows slight mutagenic effect.The percentage of abnormal cells increased with the increasing inconcentrations and time period. The common types of abnormality werec-metaphase plasmolysed cells, shifting of poles, precocious arm.Other types of abnormalities found in certain concentration are bridges,breaks in chromosome, star metaphase, fragmentation of chromosomesetc. Present observation indicates that turbugenicm, cytotoxic andmitodipressive inhibition of the spindle mechanism are the accumulativeeffects of insecticide Imidacloprid.From the observed result, it is clear that the insecticide Imidacloprid iscytologically effective chemical to the plant in different concentrationand time of treatment causing toxic effect on chromosomal behaviour.