STUDIES ON THE CYTOGENETIC AND GENETIC EFFECTS OF FLUORIDE ON BARLEY.: II. THE EFFECTS OF TREATMENTS OF SEEDLING COLEOPTILES WITH SODIUM FLUORIDE

Abstract

Treatment of seedling coleoptiles (truncated and non-truncated) with either sodium fluoride alone or in combination with dimethyl sulfoxide did not inhibit growth. Cytological analyses indicated that these treatments produced chromosome abnormalities, including bridges with or without fragments, univalents, fragments and micronuclei. The production of a significantly higher percentage of chromosomal aberrations by simultaneous treatment with a low concentration of sodium fluoride and dimethyl sulfoxide over that produced by treatment with low concentration of sodium fluoride alone indicates that dimethyl sulfoxide can enhance the uptake of the mutagen and thereby increase the mutagenic effect.Tests were conducted to determine whether the fluoride treatments were capable of inducing chlorophyll mutations. Plants whose coleoptiles had been treated at the seedling stage were self-fertilized and the S1 seeds obtained used to produce plants which were self-fertilized. The S2 seedlings obtained from these latter self-fertilizations were screened for chlorophyll mutations. None was observed.