June 1, 1925 
Variation in the Kherson Oat 
1069 
EXPERIMENTAL METHODS 
The review of selection and other 
experiments has shown conclusively 
•that the Kherson variety contains dif¬ 
ferent types. The experiments de¬ 
scribed in this study were started at 
the Akron Field Station in 1921 to ob¬ 
tain information on the genetic con¬ 
stitution of Kherson, particularly with 
regard to certain spikelet and floret 
characters. 
Kernels used in starting this study 
were selected singly from a bulk sample 
of Kherson oat, C. I. No. 459, 6 grown 
at the Akron Field Station in 1920. 
The kernels were classified and de¬ 
scribed by the system outlined by 
Coffman, Parker, and Quisenberry ( 4 ) 
in studies of theilurt oat. 
The same general system in choosing 
seed and in planting was used each year. 
In all cases the crop Was grown in the 
screened breeding garden at the Akron 
Field Station. In making the original 
seedings, kernels having an identical 
classification were sown together as a 
group. About 125 kernels were sown 
in 1921. The kernels were spaced at 3- 
inch intervals in rows 10 inches apart. 
The seed was sown on May 12 and the 
seedlings emerged May 21. The date 
of heading of each plant was recorded 
on a tag attached to the plant. Some 
plants did not mature seed because of 
unfavorable weather conditions. 
The different plants showed con¬ 
siderable variation in time of heading 
and ripening. The earliest plants 
started to head July 2, while the latest 
date of heading was July 20. Most of 
the plants headed between July 10 and 
16. At harvest the plants were pulled, 
and those of each group were tied to¬ 
gether and stored. Later, each plant 
of the group was numbered, and the 
height of culms, number of culms, num¬ 
ber of panicles, length of main panicle, 
and date of heading were recorded. 
The primary floret in the spikelets, 
rather than the plant, was used as the 
unit throughout this study. In 1921 
each of the primary florets from the 
main panicle of each plant was de¬ 
scribed. In succeeding years 25 florets 
per plant were described, and where the 
main panicle contained less than 25 
spikelets more than one panicle on the 
same plant was used in order to obtain 
a sufficient number for accurate classi¬ 
fication. The characters recorded were 
the same as those used in describing the 
original seed. 
All of the distinct characters and, so 
far as practicable, all of the different 
combinations of these characters were 
included in the 1922 studies. In mak¬ 
ing the selections for seeding in 1922 
there were sown not less than 5 nor 
more than 10 kernels having the same 
classification and from any one plant. 
In a few cases two groups of five 
kernels each from a single parent plant 
were sown. In such cases these groups 
differed in one or more characters, e. g., 
group 34 and group 35 both came from 
plant 8 of the 1921 crop (plant 8, group 
14). Kernels in group 34 bore long 
awns in 1921, while those in group 35 
were awnless. 
About 250 kernels were sown in the 
1922 experiments. The seed was sown 
April 22 and the plants emerged May 
5. An excellent stand was obtained 
and the plants made rapid growth. 
As the season was dry, it was necessary 
to irrigate them several times. 
In 1923 20 groups of kernels were 
sown. The seed was sown on May 7 
and the plants emerged May 15. Ex¬ 
cellent stands were obtained and the 
plants in most rows made very satis¬ 
factory growth. 
EXPERIMENTAL RESULTS 
About 7,000 kernels were described 
in the course of this experiment, and it 
is impracticable to include more than a 
general summary of the data obtained. 
In discussing the results the characters 
studied have been considered sepa¬ 
rately. 
SPIKELET DISARTICULATION 
In these experiments no florets were 
found which had a prominent basal 
cavity or scar resulting from dis¬ 
articulation by abscission, such as is 
characteristic of Avena sterilis, A.fatua, 
and some varieties of A. byzantina. 
Should kernels of this type occur in 
the Kherson oat, it might well be 
considered evidence of mechanical mix¬ 
ture or of hybridization. Only two 
methods of spikelet disarticulation 
were observed in Kherson. These were 
semiabscission, resulting in a slight or 
indistinct cavity, and fracture, result¬ 
ing in a rough surface with no visible 
scar. The data obtained in 1921, 1922, 
and 1923 on the inheritance of spikelet 
disarticulation are shown in Table I. 
It appears evident that heritable varia¬ 
tions exist in the method of spikelet 
disarticulation of different pedigreed 
strains of Kherson oat. Apparently 
a strong tendency exists for disarticu- 
tion by semiabscission and by fracture 
to be transmitted to the progeny in a 
high proportion of cases. 
Accession number of the Office of Cereal Investigations. 
