CYTOLOGICAL EFFECTS OF HYDROGEN FLUORIDE ON TOMATO CHROMOSOMES

Abstract

Pre-flowering plants of a highly inbred tomato line were fumigated in growth chambers with HF at a concentration of about 3 [mu]g/m3. This concentration was too low to induce visible injury up to 11 days of continuous fumigation. The experiment was run for 12 days with the 1st cytological sample taken after 4 days and then at increments of 2 days. After each period of treatment the fumigated and the control plants were removed to the greenhouse for recovery. Young leaf and flower bud smears for the treatments and the recoveries were scored for anaphase aberrations. Chromosomal aberrations found included bridges, fragments, and bridges plus fragments. All these aberrations were observed in mitosis and meiosis of the treated plants. There was a trend toward a higher percentage of chromosomal aberrations with an increase in the treatment period. In the recovery, leaf smears showed no detectable chromosomal aberrations. However, pollen mother cells showed the presence of fragments and/or bridges plus fragments but no bridges by themselves. These could be due to crossing over in heterozygous paracentric inversions. The obtained results suggest that HF may be a mutagenic agent.