CYTOLOGICAL REACTIONS INDUCED BY SODIUM FLUORIDE IN<i>ALLIUM CEPA</i>ROOT TIP CHROMOSOMES

Abstract

Fluorides are potential air pollutants in both rural and urban environments. Such compounds are exhausted into the air froin a number of industrial operations, including the production of aluminum and steel, phospate-fertilizers. and ceramics. Gaseous fluoride is readily absorbed bv leaves, but translocation to other parts of the plant is limited (naines e t al.; 1952). In most plants the absorbed fluoride is moved to the margins and tips of the leaves. According to Leone e t al. (1948) and Daines e t al. (1952) roots have a great capacity to precipitate fluoride and thus remove this substance from the plant system. Under certain conditions, however, soluble fluorides can be absorbed through the roots and transported to the leaves, producing lesions similar to those resulting from leaf absorption of fluoride compounds. As early as 1925, Dustin reported that certain chemical agents which he called poisons caryoclasiques were able to exert a toxic effect on cell nuclei without apparently injuring the cytoplasm. These agents are of interest not because of any direct toxic effects they may produce in the cell, but because of the irreversible hereditary changes they may induce in chromosomes. The present investigations were undertaken to determine the c~tological cffect of sodium fluoride solution on Allizlnz cepa root tip chromosomes. The All iz lm test (Levan 1938) reported here will not include the recovery test.