1.
A new mutable gene.
Mutable alleles have been found at the P, Bt, and Wx
loci. These mutable alleles may be described as recessives with a high mutation
rate to the dominant allele. In addition there is the genically induced
mutability of recessive a by the Dt gene. The effect of Bh on recessive c
probably belongs in this category. A new type of mutable allele has recently
been found. A dominant allele mutates with high frequency in both somatic and
germinal tissue to an intermediate allele producing light aleurone color and
red‑brownish plant color. The effect on pericarp color has not yet been
determined. An example of the mutation rate of this mutable A allele
(designated Am) is as follows: The cross of a x Am gave
74 kernels with self‑colored aleurone, 61 kernels mosaic for deep and
light colored aleurone, and 24 with light colored aleurone. At least two
different intermediate alleles, differing in intensity of color in aleurone and
plant, have been found.