Is Hydrogen Fluoride Mutagenic in Plants?

Abstract

An experiment was designed to study the cytogenetic effects of HF on tomato plants using five-week old Lycopersicon esculentum Mill. var. ''Bonny Best''. Twelve plants were grown in each of three chambers, comprising a high F treatment, low F treatment, and control. Thirty-day average concentrations of HF in the chambers were 6.7 ppB (high F), 1.2 ppB (low F), and control (no added F). Typical symptoms of HF-induced foliar injury were observed after two weeks in the high F chamber; no injury was seen on low F treated or control plants. No differences were found in numbers of fruit produced by plants exposed to the different levels of HF. Although seed weight was less in fluoride-treated plants than in control plants, these differences were not statistically significant. No significant differences were found in rates of seed germination among treatments, either on moistened filter paper, or in soil. None of the phenotypic or chromosomal abnormalities reported by Mohamed were seen in the seedlings raised in the experiment. Experiments using onion (Allium cepa L.) root-tips exposed to high concentrations of fluoride in aqueous solution produced different results. After immersion for 24 hr in 10/sup -2/ M NaF or 10/sup -2/ M NaCl,more » the number of aberrations observed in metaphase chromosomes was greater in samples exposed to NaF than NaCl.« less