FLUORIDE TOXICITY AND ITS EFFECT ON TWO VARIETIES OF SOLANUM LYCOPERSICUM

Environmental pollutants are considered to be a serious threat not only to humans but also to flora and fauna. The fluoride ion (F) as present in water, in soil, and in the atmosphere may adversely affect plants and ultimately pose a threat to plant growth and development. This study aimed to observe the effect of F on the crop productivity of tomato plants. Two tomato plant varieties (Roma and Meiguodahong) were used to study, under controlled conditions, the effect of F, in concentrations of 0, 10, 25, 50, and 100 ppm, on the parameters of seed germination, leaf area, plant growth rate, net assimilation rate (NAR), and proteomic response. The results showed that the maximum adverse effect of F on seed germination, leaf area, plant growth rate, and NAR occurred with a F concentration of 50 ppm. Compared to the control values (F=0 ppm), the respective values for the Roma (R) and Meiguodahong (M) varieties at F=50 ppm were (i) growth rate: R: 5.5 mg/day (F=0 ppm), 1.1 mg/day (F=50 ppm); M: 7.1 mg/day (F=0 ppm), 3.1mg/day (F=50 ppm); (ii) average leaf area: R: 25 cm(2) (F=0 ppm), 8 cm(2) (F=50 ppm); M: 27 cm(2) (F=0 ppm), 11cm(2) (F=50 ppm); and (iii) NAR: R: 44 mu g/day (F=0 ppm, 22 mu g/day (F=50 ppm); M: 52 mu g/day (F=0 ppm, 23 mu g/day (F=50 ppm). At a F concentration of 25 ppm, both tomato varieties over expressed a unique band, a 55 kilodalton (kDa) protein. The Meiguodahong variety was more resistant to F toxicity than the Roma variety.