Concentration- and time-dependent effects of strontium on Lens culinaris Medik.

Abstract

This study investigates how strontium (Sr) ions act on meristematic root tip cells of lentil (Lens culinaris) with changing parameters (time and concentration). Plant seeds were exposed to both a standard solution of Sr for different lengths of time (1/4, 1/2, 1, 2, 4, 8, 12, 16, 20 and 24 hours) at a fixed concentration of 1.0 molL-1 (M) and Sr ions at various concentrations (0.05, 0.1, 0.25, 0.5 and 1.0 M) for a certain length of time (12 hours). The seeds treated with Sr were made to sprout and microscopic examination focused on the root tips. The aim of microscopic examination was to clarify chromosomal abnormalities of cell division. Microscopic examination showed that various abnormalities occurred in cells of the seedlings, abnormalities such as chromosome adherence, chromosome breakings, bridge chromosomes, chromosome dispersion, chromosome shrinking, fish bones and ring chromosomes. Those abnormalities were detected several times for each treatment depending on the different periods and concentrations. Adsorption and absorption of Sr inside lentil seeds were detected by the spectroscopic method. Removed and excess amounts of Sr ions were found by spectroscopic determination. Statistical evaluation of the results was used in order to reveal the differences and similarities. The results showed that while there is a positive correlation with the concentration parameter, there is a negative correlation with the time parameter. Over 90% of Sr was removed from the solution during 12-hour exposure. Lentil seeds can be accepted as good bioaccumulators of Sr ions only for an exposure period shorter than 12 hours at an Sr concentration of 1 M.