922 
Journal of Agricultural Research 
Vol. XXX, Xo. 10 
Table II .—Behavior of F z lines from 
the three F 2 classes deficiens, inter¬ 
mediate and vulgar e y in the cross Hor- 
deum deficiens steudeliiX Manchuria; 
1923 
Classes in F 3 
Xu m-_Num- 
Type of plant De- Inter- ' Yul- 1 fern°i- 
tested 1 ficiens inedi* gare lies 
ate 
20 !__ X 20 
32 X _ 32 
( £ AX...X 1 
ficiens differ in a single genetic factor. 
The 6-rowed character may be con¬ 
sidered to be due to the factor V, the 
6 -rowed condition being developed 
only when the plant is homozygous 
for this factor. The genotype for de¬ 
ficiens would then be vv. 
Table III .—Classification of F 2 plants 
for the characters deficiens and vulgare 
in the cross Hordeum deficiens steu- 
delii X M anchuria; 1923 
groups of F 2 plants were not tested 
thoroughly in F 3 , a complete factor 
explanation will not be attempted. 
It should be pointed out, however, 
that the 6-rowed F 2 plants constitute 
approximately one-fourth of the entire 
number of plants (see Table IV), and 
that lines which segregated for 2- 
rowed versus 6-rowed gave a close ap¬ 
proximation to a ratio of three 2-rowed 
and intermediates to one 6-rowed (see 
Table V). These facts, together with 
the appearance of a low fertility’ in¬ 
termedium, indicate a two-factor ex¬ 
planation as used by Harlan and Hayes 
{6 ). These results prove that the 
low fertility intermedium factor may 
be carried by a 6-rowed variety and 
that the presence of this factor does 
not modify the expression of the factor 
for the 6-rowed condition. Two-rowed 
lacks the factors for intermedium and 
6 -rowed. Apparently the factor pairs 
which differentiate 6-rowed versus 
2 -rowed and intermedium versus 2- 
rowed are independently inherited. 
Table IV .—Distribution of plants for 
characters 2-rowed and 6-rowed in the 
F 2 generation in the cross SvanhalsX. 
Lion 
Vulgare_ 
Deficiens_ 
Intermediate. _ 
1 1 Total 
Vul- Inter- | De- : 
gare mediate ficiens ! 
147 
206 
i 
255 
608 observed. 
152 
304 
! 
! 
152 
608 calculated on a 1 : 2 :1 
basis. 
147 
461 
608 observed. 
152 ; 
i 
456 
j 
608 calculated on a 1 : 3 
basis. 
Deviation=5. P. E.=7.2. 
Svanhals crossed with Lion gave 
Fi plants which resembled the 2- 
rowed parent, but the glumes of the 
laterals were more pointed, and in some 
cases bore short awns. In the second 
generation the plants were grouped 
into four groups, 6-rowed, 2-rowed, 
intermedium, and intermediate. Only 
the 2-rowed and 6-rowed groups were 
tested thoroughly in F 3 . All of the 
plants classed as 6-rowed bred true for 
that character. Fully two-thirds of 
the plants classed as 2-rowed in F 2 
segregated in F 3 ; some produced 2- 
rowed, intermediates, and 6-rowed, 
some 2-rowed and intermedium, while 
others produced all types of F 2 . The 
intermediums obtained in F 2 are of 
the same type as those obtained by 
Harlan and Hayes (6). Strains of 
this low fertility intermedium were 
obtained from the cross SvanhalsX 
Lion, which bred true in F 3 . Since all 
Year 
Two- 
rowed 
and 
inter¬ 
medi¬ 
ates 
Six- 
rowed 
Total 
1922 
940 
319 
1,259 observed. 
944.25 
314. 75 
1, 259 calculated on a 3:1 
basis. 
i- 
4.25 
Deviation. 
10.30 
Probable error. 
1923 
i 368 
112 
480 observed. 
360 
120 
480 calculated on a 3:1 
basis. 
8 
Deviation. 
6.4 
Probable error. 
Table V .—Distribution of plants for 
the characters 2-rowed and 6-rowed 
in the F z lines which segregated, giving 
only these types and intermediates; 
cross SvanhalsX Lion 
Two- I 
rowed Six- | Total 
and inter- rowed 
mediates 
33 
12 
45. 
27 
13 
40. 
35 
9 
: 44. 
34 
13 
47. 
129 
47 
176 
132 
44 
176 
3. 87 
Deviation. 
Probable error. 
