Inheritance of Salmon Silk Color in Maize 
547 
To test for the occurrence of salmon silks on green plants of the consti- 
tution R° A b PI or R° A b pl, a dilute purple plant with salmon silks 
was crossed with a green plant of the constitution R° A b pl. Two of 
the Fi plants were selfed. Purple seeds only were planted. These 
gave 44 dilute purples and dilute sun reds, of which 32 had green silks and 
12 had salmon. There were 25 green plants, R g A b, 18 of which had green 
silks; the other 7 had typical salmon and brown silks. 
From these two tests, it may be concluded that salmon silk color is 
not dependent on the R factor nor is it noticeably influenced thereby. 
This is similar to the relation between red pericarp color and R g (Emerson, 
1.921). 
Summary of inheritance 
Salmon and brown silks are recessive to green silks by a single factor 
pair, Sm sm. 
This factor, Sm, is independent in inheritance from P (pericarp), 
A (aleurone and plant color), B (plant color), and R (aleurone, plant color, 
cherry pericarp, and red silk color). 
It is linked with the factor PI (plant color), and consequently also with 
Y (yellow endosperm). 
Dominant A is necessary for the production of salmon or brown silk 
color; that is, the combination a a sm sm is green. 
The intensity of pigmentation of salmon-brown silks is directly related 
to the intensity of pigmentation of the pericarp. 
The relation of the factors A, Sm, and P to silk color may be represented 
schematically as follows: 
A Sm P = Green a Sm P = Green 
A Sm p — Green a Sm p = Green 
A sm P — Salmon a sm P — Green 
A sm p — Brown a sm p = Green 
linkage relations of Y, PI, and Sm 
Preliminary tests of linkage of PI and Sm 
The first indication of the linkage of the Sm and PI factors was observed 
in the progeny of an outcross of the original salmon with a purple plant 
having green silks. This plant proved to be heterozygous for both Sm 
