Induction of Mitotic Abnormalities in Ornithogalum virens by Tritiated Thymidine

Abstract

Mitotic abnormalities in Ornithogalum virens Lindl. were studied by using tritiated thymidine as an internal mutagen. Two concentrations viz., 1.0μCi/ml and 2.0μCi, /ml tritiated thymidine were used in this investigation. The root tips were grown in the isotope solution for 4, 6 and 8 hours respectively and then they were transfered to isotope free nutrient solution for further growth of 6, 12, 18 and 24 hours respectively. Cells were scored at both metaphase and anaphases for various types of chromosomal aberrations. Chromatid and isochromatid breaks, chromatid intrachanges, severe chromosome fragmentation, chromosome rings, binucleate cells, single lagging chromosome at metaphase, tetraploid cells were the important types of aberrations observed. It was noticed that 2.0μCi/ml H³ thymidine concentration has caused a higher frequency of chromosomal aberrations than that of 1.0μCi/ml H³ thymidine concentration.