Hayes and Garber - Cucurbit Breeding

186 BREEDING CROP PLANTS
manner as in the flint-flour cross, the difficulty of
what similar
a correct classification by inspection is apparent.
The endosperm of corn may be either yellow, pale yellow,
or white. In some crosses there is almost complete dominance of
the yellow color, while in other crosses the FI is intermediate or
pale yellow. The results of most yellow-white crosses may be
explained by one factor or by two multiple factors. It is impossible
to tell by inspection whether a particular yellow variety contains
one or two factors for yellow. The only sure method is
FIG. 43. Two first year self-fertilized ears of Minn. No. 23 showing the lethal
endosperm character.
to note whether the segregation approaches 3:1 or 15:1. White
(1917) has recorded a cross in pop corns between yellow and
white endosperm varieties in which white is the dominant character.
The results were explained by supposing that the white
variety carried an inhibitory factor, A, and also a factor for
yellow or Y, while the zygotic condition of the yellow variety
was YY.
The inheritance of aleurone color is even more complex than
the inheritance of yellow endosperm color. The aleurone may
be either colorless, mottled, red, or purple. Three factors are