FACTORS FOR YIELD AND QUALITY OF SPRING WHEAT 
19 
in this F 3 study. The number of plants recorded, therefore, is less 
than in the case of the characters previously studied. 
Table 19. — Breeding behavior in the F z generation of white and red kernel classes 
and 10,121 plants of Marquis-Hard Federation wheat crosses grown at Bozeman, 
Mont., in 1924 
F2 families 
Number of F3 plants by ker- 
nel color 
Devia- 
Fa classes and breeding be- 
havior in tbe F 3 generation 
Number 
Expect- 
ed on 
7:4:4 
ratio 1 
Red . White 
i 
Total 
tion 
from ratio 
indicated 
Probable 
error . 
Kernels white: 
White 
16 
763 
763 
4,476 
1,943 
2,939 
Kernels red: 
Red. 
101 
43 
64 
97 
56 
55 
4,476 i 
Red and white- 
1 
1,485 ! 458 
2,734 205 
28 
21 
12.87 
8.84 
Total 
224 
8,695 ! 1,426 
10, 121 
1 P=0.10. 
The data given in Table 19 show that the white-kern eled strains 
bred true and that the red ones either bred true or segregated in a 
3:1 or 15:1 ratio, in proportions approximating a 7:4:4 ratio. 
There was a slight excess of true-breeding red-kerneled F 2 families, 
and also the number of families having two factors or breeding in a 
15:1 ratio was somewhat larger than expected on a 7:4:4 ratio. 
This excess may be 
due to the selection of 
a part of the material 
for dark-red color. 
This also might have 
caused a shortage in 
the number of fami- 
lies segregating in the 
3:1 ratio. The devi- 
ations in numbers of 
both segregating 
groups are less than 
three times their 
probable errors, thus 
indicating a close fit. 
HEADING PERIOD 
M 
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&0^<EMs4/</ 
/ 
— ' — 
K 
v , 
A 
V^ 
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/ 
\ 
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f 
> 
K 
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7 /& /S /& /& ^^^S S/ 
Early maturity 
usually has been con- 
sidered one of the 
important factors for 
improvement in 
varietal adaptation 
under droughty con- 
ditions. Under favorable conditions, however, earliness seldom 
is considered an advantage and when obtained usually results in a 
Fig. 1.— Frequency distribution of F2 and F3 hybrid wheat plants 
and the range of variation of the Marquis and Hard Federation 
parents, together with their average dates of heading at Bozeman, 
Mont., in 1923 and 1924 
