June 7, 1924 A Genetic and Cytohgical Study of Wheat Hybrids 1021 
that segregates with a chromosome number intermediate between 14 and 21 
can be obtained in a completely fertile and homozygous condition. 
GENETIC INHERITANCE IN SPECIES CROSSES 
Most of the characters studied in these various crosses do not appear to segre¬ 
gate in a simple Mendelian manner, and the percentage of homozygous individuals 
resembling one parent or the other are in most cases comparatively small. In 
the case of the cross Marquis X Alaska, the F 2 classification has been checked 
by growing the F 3 and the same general conclusions have been verified. There 
are, however, two or three characters which seem to segregate in the usual Men¬ 
delian manner, indicating perhaps that these characters are dependent on factors 
in the 14 primary chromosomes which behave in a normal manner in the reduc¬ 
tion division. Some of the more typical characters are shown in Table II, to 
illustrate the inheritance of those characters which seemHo segregate in a Men¬ 
delian manner and those which show no clear segregation into definite Men¬ 
delian ratios. 
Table II .—Segregation of certain characters in F 2 of various crosses of wheat species 
Length of awns in centimeters 
Cross 
Tips 
1 
2-3 
4-10 
4-10 
10+ 
n 
1. Marquis X Kubanka_ 
48 
53 
9 
17 
8 
135 
2. Hybrid 143 X Alaska__ 
188 
36 
8 
57 
3 
292 
3. Marquis X Alaska... 
65 
42 
14 
14 
17 
152 
4. Hybrid 143 X Polish..:_ 
48 
11 
5 
13 
5 
82 
5. Amby X Kubanka. _. 
36 
10 
2 
4 
52 
TYPE OF KEEL 
Cross 
Vulgare 
Inter¬ 
mediate 
Durum 
n 
1.......... 
36 
55 
44 
135 
2__________ 
86 
87 
120 
293 
3_____,___ 
38 
85 
29 
152 
4........ 
7 
56 
19 
82 
5 . ... . ... 
15 
26 
11 
52 
AWN COLOR 
Cross 
Yellow 
Brown 
Black 
2 . .. .... 
105 
56 
84 
3 _ . _ _ 
77 
13 
62 
GRAIN TEXTURE 
Cross 
Very 
hard 
Hard 
Inter¬ 
mediate 
Starchy 
Very 
starchy 
n 
1 . . 
50 
63 
3 
1 
117 
2 . . 
24 
51 
77 
47 
199 
3...... 
24 
76 
36 
9 
2 
147 
4... 
21 
41 
2 
4 
68 
5...... 
1 
26 
6 
9 
7 
49 
