Soybean (Glycine max [L.] merrill) as a short-term assay for study of environmental mutagens. A report of the U.S. Environmental Protection Agency Gene-Tox Program.

The soybean (Glycine max [L.] Merrill) spot test is suggested as a preliminary screening test for environmental mutagens. This system makes use of various types of spots that originate from the treatment of seeds or seedlings with mutagens. The homozygous dominant y11y11 dark green leaves may show light green and very dark green spots; the heterozygous y11y11 light green leaves may show dark green, yellow or twin spots; and the homozygous recessive y11y11 yellow leaves show light green receptors. The interpretation is that twin spots on the y11y11 leaves originate from somatic crossing-over, and the singles originate primarily from losses or gains of the segments or chromosome carrying the gene y11 or y11. The yellow plants (y11y11) can produce light green sectors if y11 mutates to y11. Studies carried out with a host of chemical and physical agents lend support to the idea that the soybean system can distinguish between several genetic mechanisms underlying the formation of spots. Spots are detected against their native genetic and phenotype background, thus minimizing the effects due to physiological changes. The system is rapid (4-5 weeks per chemical), inexpensive, and involves an eukaryotic organism. It has the advantage of being adaptable for liquid solutions of chemicals, solid wastes, emulsions of chemicals (e.g., in lanolin), and gaseous products.