Genvetics: Teas and Anderson

In studies on the induction of gene mutations by high energy radiation from the Bikini atom bomb, X-ray and other sources, a large number of seedling cultures have been grown for observation. Since January, 1949, maize seedling cultures have been observed by the use of filtered ultraviolet light. Normal seedlings viewed by ultraviolet light have a dull reddish-purple appearance due to the red fluorescence of chlorophyll plus the reflection of a small amount of visible blue-violet light from the lamp. ' Several cultures, all originating from a single seed exposed at Bikini, showed segregation of a mutant type which exhibited an intense bluish-white fluorescence. In daylight no difference could be seen between the blue-fluorescent and normal seedlings. The fluorescence varies somewhat from plant to plant, both in extent and in the time or rate of development. The fluorescence increases with the age of the plants until about the four-leaf stage, then decreases and is seldom observed in plants over two feet in height. Usually the first leaf shows the most intense fluorescence. At the time of pollen shedding, anthers in the tassel fluoresce bluish-white, even more brilliantly than the seedlings. This fluorescence is localized in the anther walls. The immature pollen also fluoresces slightly, mature pollen not at all. Chemistry.-Acetone extracts of blue-fluorescent seedlings or anthers chromatographed on CaCO1 columns showed two blue fluorescent bands running some distance behind the chlorophylls. Ascending paper strip chromatograms using Whatman No. 1 paper with water saturated butanol gave much clearer resolution of blue-fluorescent components, revealing three well-defined blue-fluorescent spots. Subsequent two-dimensional chromatograms have shown up to six additional blue-fluorescent spots, fainter than the first three. The major spots were arbitrarily called A, B, and C in order of increasing Rf values. The possibility that some or all of the blue-fluorescent spots are artifacts produced in extraction was tested by chromatograms of anthers and seedlings in which the fresh plant tissue was crushed directly on the paper. The three major spots in this case appeared in the same positions as when acetone extracts were used. A, B, and C as well as some available blue-fluorescent compounds were chromatographed in butanol-water, butanol-water with ammonia, and butanol-water with hydrochloric acid