THE MMS DOSE RESPONSE FOR CHROMOSOMAL ALTERATIONS IN BARLEY

Resumen

Dose response curves for the chromosomal alterations induced by the monofunctionaly alkylating agent MMS in barley root tip meristem were obtained. The chromosomal alterations scored at anaphase were chromatid and isochromatid fragments, bridges and lagging chromosomes. In addition at the interphase stage,
In most of the cases analyzed, a straight line was found except for the lagging chromosomes and the micronuclei which were fitted the best to an exponential expression. The lagging chromosomes were found not to fit Poisson distribution, implying the non randomnes of the behavior of MMS. The action of MMS on
the cellular division of the barley root tip meristems was also investigated finding a direct decrease with the increase of the dose and it was reflected in the number of anaphases per root meristem and in the mitotic index.