July 1, 1925 
Productiveness and Deleterious Characters in Corn 
91 
EXPERIMENTS WITH SELF-FERTILIZED LINES 
Systematic selection within self-fertilized lines in several varieties 
has given comparatively quick results in the isolation of strains with 
distinct characteristics. In addition, it has afforded a view of some 
indirect effects of selection that could not be seen in the studies with 
open-fertilized material. Some of the results are given in the fol¬ 
lowing pages. 
EFFECT OF SELECTION UPON THE NUMBER OF ROWS OF KERNELS 
Many plants of the Garrick variety were selfed in 1916 and good 
seed ears were selected from these to represent six classes with different 
numbers of kernel rows on an ear. These ranged from 8 to 18 rows, 
inclusive. These classes were maintained in the succeeding years by 
continuous selection. The effect of the selection during. the first 
five years upon the percentage of progeny ears having the same num¬ 
ber of kernel rows as the parent ear is shown in Table VIII. 
Table VIII. — Data on the effect of selecting continuously within selfed lines for 
different numbers of kernel rows , upon the percentages of the progeny conforming 
to the parental number of kernel rows 
Kind of data 
Kernel 
rows on 
Years in which the progeny were grown 
parent 
ears 
1917 
1918 
1919 
1920 
1921 
Number of parent ears__ 
8 
18 
8 
15 
52 
49 
10 
24 
8 
19 
64 
69 
12 
24 
5 
11 
53 
76 
14 
21 
4 
10 
52 
76 
16 
18 
4 
8 
37 
40 
18 
3 
4 
2 
15 
16 
Number of progeny ears classified_ 
8 
3,265 
1,076 
2,653 
3,486 
2,563 
2,499 
10 
4,790 
1,050 
3,513 
4,642 
12 
4,903 
597 
1,750 
2,352 
3,804 
14 
3,095 
498 
1,198 
2,147 
3,432 
16 
3,410 
441 
835 
1,332 
530 
Per cent 
1,516 
18 
572 
Per cent 
477 
Per cent 
197 
Per cent 
612 
Per cent 
Percentages of progeny ears having the 
8 
21.2 
25.4 
47.7 
68.6 
85.6 
same number of kernel rows as the par¬ 
10 
45.9 
44.2 
55.9 
63.1 
66.5 
ent ear. 
. 12 
38.7 
38.6 
44.9 
46.8 
52.9 
14 
19.1 
30.6 
33.6 
36.3 
50.3 
16 
11.8 
13.0 
26.1 
32.9 
43.9 
18 
8.6 
4.2 
19.7 
22.5 
43.8 
Highest percentage of progeny ears in an 
8 
35.9 
32.3 
86.6 
100.0 
100.0 
individual ear row having the same num¬ 
10 
66.2 
56.8 
75.7 
93.3 
95.0 
ber of kernel rows as the parent ear. 
12 
51.0 
49.0 
66.9 
81.3 
77.0 
14 
46.2 
35.0 
45.8 
64.3 
88.0 
16 
26.3 
20.6 
33.9 
59.3 
63.0 
18 
25.8 
11.3 
30.9 
46.2 
60.0 
With the exception of the 10, 12, and 18 rowed classes in 1918, 
there was an annual increase throughout the five years in the degree 
to which the progeny ears in each class conformed to the parental 
character. The rate of increase, however, was not the same for each 
class. In the parent variety the mode for number of kernel rows 
was 12. During the first three selfed generations the 10-rowed class 
led in percentage of conformity to the parental number and the 
8-rowed group took and maintained the lead after that. In the data 
for 1920 and 1921 the percentage of conformity to the parental num¬ 
ber tended to be inversely proportional to the number of rows on the 
ears. 
