June 1, 1925 
Variation in the Kherson Oat 
1079 
The data obtained on the inheritance 
of awns in the Kherson oat in 1923 
were similar to those of previous seasons 
in many respects. Although the per¬ 
centage of progeny of kernels described 
as bearing twisted awns was smaller in 
1923 than in 1922, it was much larger 
than that of 1921. The breeding be¬ 
havior of the kernels having non- 
twisted long awns was very similar in 
1923 to that of 1921, and awnless 
parental kernels indicated a very strong 
tendency to produce only awnless prog¬ 
eny. 
The data on inheritance of awns 
clearly indicate that genetically three 
types of awns exist in the Kherson oat. 
All three types tend to breed true. 
The twisted awn appears to breed as a 
recessive. Possibly because of physio¬ 
logical influences, some kernels which 
carry the factor for producing this type 
of awn fail to produce awns at all or 
produce the other types. The non¬ 
twisted long awn in Kherson is much 
less definite in breeding behavior than 
is the twisted awn. The nontwisted 
short awn in Kherson probably results 
from chance variation. Its genetic 
constitution probably is similar to the 
nontwisted long awn. It appears 
probable that pure-breeding strains 
which bear long awns can be isolated 
from the variety. The data for each 
group show more clearly than do the 
summaries for all groups that many 
pure-breeding awnless strains exist in 
Kherson oat, although not all awnless 
strains breed true for that condition. 
Nilsson-Ehle (17) has stated that 
external conditions may greatly influ¬ 
ence the production of awns in culti¬ 
vated oat varieties. The junior author 
in classification studies of oats con¬ 
ducted at widely separated points in the 
United States has observed that the 
number of awns in some varieties and 
strains varies apparently with environ¬ 
mental conditions. For this reason it 
can not be assumed that these Kherson 
strains would show a similar behavior 
for awns under a decidedly different 
set of conditions. 
The awn types found in the present 
study of Kherson oats are shown in 
Plates 2 and 4. 
LEMMA COLOR 
Only three lemma colors have been 
recognized in this study of the Kherson 
variety. These colors, reddish yellow, 
yellow, and white, have been described 
previously (pi. 4). Table V presents the 
data on color in 1921, 1922, and 1923, 
and shows conclusively that the yellow 
color is the most stable in breeding behav-. 
ior. Both of the o ther kernel colors tend 
to break up and produce more progeny 
described as yellow than of the other 
types. The distinctions between the 
different color classes in oats are often 
difficult to make, as the colors grade 
into one another. This is due partly 
to the effects of physiological influences, 
which may cause genetically white 
kernels to be called yellow or yellow 
kernels to appear either reddish yellow 
or white. 
Table V.— Inheritance of lemma color 
in strains of the Kherson oat grown 
at the Akron Field Station, Akron, 
Colo., in 1921, 1922, and 1923 
DATA FOR 1921 
