Jan. 1, 1925 
A Study of Variability in the Burt Oat 
31 
Table II. — Data on inheritance of three different methods of spikelet disarticula¬ 
tion in the progeny of selected kernels of each of eight strains of the Burt oat when 
grown at the Akron Field Station in 1921 
Kernels in progeny 
Strain number and method of disarticula¬ 
tion in parent kernels 
Number disarticulating 
by— 
Percentage disarticulating 
by— 
Abscis¬ 
sion 
Semiab¬ 
scission 
Fracture 
Abscis¬ 
sion 
Semiab¬ 
scission 
Fracture 
Kansas No. 5020: 
Semiabscission_ 
266 
449 
34 
35. 5 
60.0 
4.5 
Fracture__ ___ 
0 
108 
195 
0 
35. 6 
64.4 
Kansas No. 5211: 
Abscission.. ... . _ _ ___ 
1,135 
111 
2 
90.9 
8.9 
.2 
Semiabse ssion_ 
41 
418 
108 
7. 2 
73. 7 
19.1 
Fracture_ 
73 
337 
926 
5.5 
25.2 
69.3 
Kansas No 5220: 
Abscission_ ... 
91 
0 
0 
100.0 
0 
0 
Semiabscission_ 
1 
144 
6 
.6 
95.4 
4.0 
Fracture... _ 
0 
144 
180 
0 
44. 4 
55.6 
Kansas No. 6004: 
Fracture_ 
0 
0 
29 
0 
0 
100.0 
Kansas No. 6052: 
Semiabscission_ 
* 0 
73 
4 
0 
94.8 
5.2 
Fracture_ 
0 
‘ 114 
147 
0 
43.7 
56.3 
Kansas No.6076: 
Abscission_ 
0 
0 
6 
0 
0 
100.0 
Semiabscission_ 
53 
158 
44 
20.8 
61.9 
17.3 
Fracture_ 
0 
14 
262 
0 
5.1 
94.9 
Kansas No. 6090: 
Abscission_ 
345 
20 
0 
94.5 
5.5 
0 
Semiabscission_ 
63 
117 
8 
33.5 
62.2 
4.3 
Fracture_ 
0 
112 
71 
0 
61. 2 
38.8 
Kansas No 6094: 
Absci ssion_ 
130 
1 
0 
99.2 
0.8 
0 
Semiabscission_ 
109 
21 
9 
78.4 
15. 1 
6.5 
Fracture_ 
0 
151 
87 
0 
63.4 
36.6 
All strains: 
Abscission_ 
1,701 
132 
8 
92.4 
7.2 
.4 
Semiabscission_ 
533 
1, 380 
980 
213 
25. 1 
64.9 
10.0 
Fracture_ 
73 
1,897 
2.5 
33.2 
64.3 
STUDY IN 1920 
Table III presents the data on floret 
disjunction for each strain grown at Ak¬ 
ron and Manhattan in 1920. The num¬ 
bers of kernels studied and percentages 
falling into each disjunction class are 
given. The combined data for all strains 
at each station and at both stations are 
shown also. The parental kernels sown 
in 1920 were separated into only two 
classes for disjunction. The kernels 
properly representing the intermediate 
class (heterofracture) probably went 
mostly into the basifracture class. 
A study of the data on floret dis¬ 
junction in the 1920 crop indicates 
that the sativa type (which disarticu¬ 
lates) is much more stable in breeding 
behavior than the sterilis type (which 
separates by basifracture). More than 
67 per cent of the progeny kernels 
produced at both Akron and Man¬ 
hattan from parental kernels dis¬ 
joining by disarticulation were describ¬ 
ed as disarticulating, slightly less than 
23 per cent as separating by hetero¬ 
fracture, and only 10 per cent as 
separating by basifracture. 
Only 18.3 per cent of progeny kernels 
in which disjunction took place by basi¬ 
fracture were produced from parental 
kernels so classed. More than twice 
as many of the 1920 progeny from ker¬ 
nels of this class, or 47.1 per cent, were 
described as disjoining by disarticula¬ 
tion as by basifracture, while in 34.6 
per cent disjunction was described as 
by heterofracture. 
Comparatively few of the kernels in 
which floret disjunction was classed as 
taking place by basifracture bred true 
in 1920. These data indicate that in 
this material the disarticulation form 
is more stable in breeding behavior 
than the basifracture form of disjunc¬ 
tion. 
The summarized data for each of the 
two stations show that the percentage of 
progeny kernels disjoining by disarticu¬ 
lation, and produced from parental ker¬ 
nels so classed, was about 66 per cent at 
Akron and 73 per cent at Manhattan. 
The percentage of progeny kernels dis¬ 
joining by heterofracture and grown from 
parent kernels in which disjunction was 
classed as by disarticulation and as by 
basifracture varied considerably at the 
