1. The symbol Yr is now established to designate the gene for pale­-yellow seeds (Maize Genetics Cošp. News Letter No. 22. 1948), since it controls the shade in a yellow base. Crosses with ms1 and po gave the following results:

 

Total of ears selfed

Color of the seeds

Plants

Medium % of germination

+

ms1

3

Yellow‑orange

199

28

60

 

Pale‑yellow

56

15

64

 

White

21

107

68

 

 

 

+

po

 

3

Yellow‑orange

161

19

70

 

Pale‑yellow

27

12

70

 

White

25

59

86

 

The interrelations between YD and YR are as follows:

 

YD

--

YR

--

Yellow‑orange

YD

--

Yr

Yr

 

Yd

Yd

YR

--

Yellow

Yd

Yd

Yr

Yr

Pale‑yellow.

 

The separation of yellow‑orange and yellow seeds is sometimes difficult, the segregation obtained being 15:1 pale‑yellow. The pale‑yellow seeds in some crosses are very pale and could be confused with the white ones.