Jan. 1, 1925 
A Study of Variability in the Burt Oat 
15 
Wiggans 18 studied the behavior of 
the awn character in the cross Red 
Texas X Swedish Select. The Fi 
spikelets possessed only one awn and 
this was slightly twisted and bent, a 
typical intermediate condition. The 
F 2 plants were classified in regard to 
awns per spikelet as ( 1 ) one strong 
awn ( 2 ) one intermediate awn (3) 
one weak awn, and (4) two weak awns. 
The last two classes proved to be the 
same in their breeding behavior and 
should be considered as one class. If 
this is done a close approximation to 
the following ratio is obtained: 1 (one 
strong awn): 2 (one intermediate awn): 
1 (one or two weak awns). These 
results indicate that one pair of factors 
determine the kind of awns in this 
particular cross, although both parents 
contain at least one other factor for 
awning. 
It was found that yellow plants 
practically always had either one weak 
awn or two weak awns on each spikelet 
and that the plants classified as whites 
generally had only one awn to the 
spikelet and this one was strong in the 
majority of cases. There are indica¬ 
tions of a strong linkage between the 
yellow color and the weak-awned con¬ 
dition. The linkage between white 
color and strong-awned spikelets was 
not so strong as that between yellow 
color and weak awns but is significant. 
In the cross Burt X Sixty-Day 
Fraser (37) found nearly complete 
dominance of the awnless condition. 
According to Fraser both parents carry 
the factor for awning, but this factor 
was ^prevented from operating in Sixty- 
Day by an inhibitor linked with yellow 
color. In the first generation the 
production of awned plants is depend¬ 
ent on the extent of dominance which 
this inhibitor displays, which in turn 
probably is dependent on environ¬ 
mental factors. In F 2 , awnless, partly 
awned, and fully awned plants are 
produced approximately in the ratio 
of 1 : 2 : 1 , the ratio of plants not 
fully awned to plants fully, awned 
being close to 3 : 1 . The fully awned 
plants when tested in F 3 proved to be 
pure recessives. Nearly all partly 
awned plants were heterozygous and 
gave ratios of approximately 3 plants 
not fully awned to 1 fully awned. 
The awnless F 2 plants were of two 
kinds, those breeding true, or practi¬ 
cally so, and those which segregated in 
a manner similar to an Fi plant. 
Zhegalov (160) has reported the 
results of a number of species crossed 
in oats and discusses the inheritance 
of awns and other characters in these 
crosses. 
Marquand (75) found that the 
percentage of awned spikelets in 
panicles taken from unselected varieties 
is constant on the whole, and unaffected 
by external conditions though probably 
dependent upon multiple factors. 
LEMMA COLOR 
In this review it is understood that 
all references made by the various 
authors to color of glumes, kernels, and 
grain were intended to apply to the 
floret and more definitely to the lemma 
or flowering glumes. 
Kornicke and Werner (64) in their 
classification of oats used lemma color 
to distinguish the main groups of 
varieties of Avena sativa and Avena 
orientalis. 
Von Tschermak (136) found that 
black color in the glumes was dominant 
over the light or yellowish color. 
Wilson (151) crossed Black Tartarian 
oats with Goldfinder, a white oat. The 
Fi plants had rich brown grains. In 
F 2 , black, brown, yellow, and white 
kernels could be distinguished. By 
including the blacks and browns in a 
dark-kerneled class and the yellows 
and whites in a light-kerneled class, 
a ratio of 2.99 of the former to 1 of the 
latter was obtained. Other crosses 
between Black Tartarian and white- 
seeded varieties gave results in F 2 
which clearly indicated the dominance 
of dark-kernel color. 
Norton (99) found that black and 
white oats when crossed gave a brown 
hybrid in Fi, but in F 2 they produced a 
ratio of 1 black: 2 brown: 1 white. In 
succeeding generations the extracted 
black and the extracted white types 
bred true. 
Roberts and Freeman (114) studied 
an apparent genetic alteration of the 
color type of Red Texas oats from red 
to black under Kansas conditions but 
found that close-pollinated plants of 
each sort yielded seed which came true, 
indicating no sporting of one variation 
from the other. 
Nilsson-Ehle (91) noted a slight 
variation in the lemma colors of oats 
as the result of environment, although 
he believed that in the main they tend 
to breed true. He found the range of 
variation in dark-colored florets to be 
from black to brown or brown to black. 
Crosses of the following types were 
made: Black X white, yellow X white, 
gray X white, black X yellow. In 
crossing black and white oats he found 
18 Wiggans, R. G. op. cit. 
