5. New mutable loci.

Two new unstable genes were found in material provided by E. G. Anderson which had been exposed to irradiation from the Bikini atom bomb. Good F₂ ratios are found. One of these mutable genes is luteus which mutates to normal giving plants with green stripes on luteus background. The mutability of this allele is autonomous in that its rate is not influenced by the action of other loci. The second unstable type is a mutable pale green but the mutability of this gene is apparently controlled by the action of another gene which segregates independently. This latter case is similar to the a‑Dt situation and to the Activator type of induced mutubility which is being so extensively studied by McClintock.

M. M. Rhoades and

Ellen Dempsey