12 
BULLETIN 1403, U. S. DEPARTMENT OF AGRICULTURE 
The segregation of the Bozeman material into the three classes 
conformed closely to a 1 :12 : 3 ratio, and that of the Moccasin mate- 
rial was near a 1:11:4 ratio. It was therefore necessary to make a 
careful study of the F 3 material to determine the breeding behavior 
of the different classes. This study was made at Bozeman in 1924 
on material grown from F 2 Bozeman seed. The behavior of the three 
classes in the F 3 generation is presented in Table 8. 
Table 8. — Breeding behavior in the Fz generation of 12,197 plants from Marquis- 
Hard Federation wheat crosses of the three awnedness classes grown at Bozeman, 
Mont., in 1924 
F2 classes and their breeding 
behavior in the F3 generation 
F2 families 
Number of F3 plants by awnedness 
classes 
Corrected 
Number 
Percent- 
age of 
class 
1, awnless 
2, apical- 
ly awn- 
letted 
3, awn- 
letted 
Total 
percent- 
age of F2 
1, awnless: 
1 
26 
4 
1 
83.9 
12.9 
3.2 
1,382 
62 
4 
1,382 
239 
48 
5.41 
1 and2 
177 
30 
.83 
1, 2, and3 
14 
.21 
Total 
31 
100.0 
1,448 
207 
14 
1,669 
6.45 
2, apically awnletted: 
1 
1 
17 
23 
44 
56 
9 
.7 
11.3 
15.3 
29.3 
37.3 
6.0 
46 
46 
946 
1,178 
2,504 
2,970 
476 
.51 
2 
946 
900 
1,683 
8.52 
1 and 2 
278 
185 
11.53 
1, 2, and 3 . 
636 
22.06 
2 and 3 
1,699 1.271 
28.08 
3 
476 
4.51 
Total . 
150 
99.9 
509 
5,228 ; 2,383 
8,120 
75.21 
3, awnletted: 
3 
43 
100.0 
2,408 
2,408 
18.34 
Grand total 
224 
300.0 
1, 957 
5, 435 4. 805 
12, 197 
100.00 
To interpret the data on a one-factor basis there must necessarily 
be approximately 25 per cent of true-breeding recessives. These 
recessives may be among those plants having either more or less awn 
development than the F 1} which was apically awnletted (class 2) and 
intermediate between the two parents. 
In the F 2 generation, combining classes 1 and 2, the plants as 
classified gave the percentages shown in Table 9. 
Table 
-Percentage totals of F 2 results by combining classes 1 and 2 in comparison 
with class 3 
Localities 
Classes clflSS o 
land 2 1 Llass 6 
i 
81.7 j 18.3 
73.3 j 26.7 
78.0 ! 22.0 
The awnletted class 3 from Bozeman material bred true in the 
F 3 generation, and as shown in Table 8 nine families also bred true 
for class 3 that had been described in F 2 as belonging to class 2. 
