14 
Journal oj Agricultural Research 
Vol. XXX, No. 1 
Etheridge (33) in his classification of 
oat varieties made use of the awn as a 
character of secondary importance. 
He states that the geniculate awns 
appear abundantly only in a few half¬ 
wild varieties, but in such cases they 
are recognized as a distinguishing char¬ 
acter. It is not believed by the present 
writers that this statement of Etheridge 
is fully justified, as some of our most 
valuable cultivated varieties, such as 
Swedish Select, normally have this type 
of awn. 
Etheridge (33) found that in respect 
to presence or absence of awns, together 
with their form, the varieties under 
study have remained constant. In his 
review of the work of different authors 
he states that Kornicke and Werner 
(64) made the primary division of the 
principal groups of oats according to 
the number of awns per spikelet, that 
Denaiffe and Sirodot (26) used the awn 
as a distinction between varieties, that 
Atterberg (5), Nilsson (89), and Bohmer 
(10) made no use of the awn, and that 
Broili (12) believed the awn to be of 
little or no value in classifying oat 
varieties. 
Surface (127), in crossing Avena fatua 
with Avena saliva, variety Kherson, 
found the Fi to bear awns on only the 
lower floret and that the second floret 
of the spikelet was never awned. In 
F 2 he found stout awns on the lower 
floret and awns on the upper floret, both 
correlated with the fatua type of base. 
He found a slightly greater proportion 
of the yellow-kerneled plants than of 
the other colors which were.awnless but 
did not consider the difference signifi¬ 
cant. According to Surface there did 
not seem to be any marked correlation 
between yellow color and absence of 
awn in this cross. 
Love and Fraser (69) made a cross 
between Burt, a weak-awned 16 variety, 
and an awnless strain of Sixty-Day and 
observed that the Fi plants were almost 
awnless. In F 2 a ratio of approxi¬ 
mately 2 awned to 1 awnless plant was 
found. In F 3 the fully awned forms 
bred as pure recessives, the partially 
awned plants bred in the ratio of 3 
awnless to 1 awned, and certain awn¬ 
less F 2 plants apparently were hetero¬ 
zygous as they produced awns in F 3 . 
Love and Fraser do not believe the 
yellow color in Burt carries the in¬ 
hibitor for awns as does the yellow 
color in Kherson. According to these 
authors it appears that the yellow color 
in Sixty-Day carries an inhibitor for 
awn development. 
In the cross Red Texas X Sixty-Dav 
the same authors found only 1.3 per 
cent of awns in Fi. The awnlessness 
of the Sixty-Day parent apparently 
was dominant in Fi over the weak- 
awned type. In F 2 an approximation 
of the 1:2:1 ratio was observed. The 
fully awned type was found to breed 
as a pure recessive, partially awned 
types were shown to be heterozygous, 
and awnless F 2 plants broke up in F 3 , 
showing that not all awnless F 2 plants 
can be considered as pure dominants. 
Love and Fraser state that weak awns 
and awnlessness in oats probably are 
due to a 1 -factor difference. Sixty-Day 
may carry an inhibitor for awn devel¬ 
opment linked with the yellow color, 
but Burt evidently does not carry such 
an inhibitor, as awned yellow Burt 
types are found in numbers. 
In a cross of the strong-awned Avena 
fatua with the awnless Sixty-Day the 
same authors found Fi to be interme¬ 
diate. In F», 133 awnless, 215 inter¬ 
mediate, and 112 plants exhibiting the 
“wild” type were found. These au¬ 
thors state that in the Burt variety, 
which they consider a sterilis type, the 
fully awned condition was correlated 
with the Burt type of disjunction and 
midlength basal hairs. They also state 
that 2 -awned spikelets are found only 
in fully awned panicles. 
Wilds 17 studied the inheritance of 
awn type in crosses of Avena fatua with 
Tartar King and Sixty-Day. The 
strong awn was found recessive to the 
awn of intermediate type (awnless) 
and partially awned plants were con¬ 
sidered as dominants. 
Love and Craig (70) reported that, 
in a cross of Avena fatua and Avena 
sativa , variety Sixty-Day, the Fj was 
intermediate and that there was some 
relation between the yellow color and 
the absence of awns. In another paper 
(71) they state that for the “weak” 
awn the fully awned condition is reces¬ 
sive and the character seems to occur 
in a simple 1 : 2:1 ratio. 
Meunissier (77) considers that the 
awn is a fluctuating character. He 
states that there are strains of oats 
mostly much awned, others which have 
very few awns, and still others which 
are entirely without awns. Absence 
of the awn appears to be clearly a reces¬ 
sive character. He states that the 
twisting of the awn is sinistrorse (in a 
spiral to the left). 
ia xhe “weak” awn class of Love and Fraser includes the “nontwisted” awn class described in the present 
paper. 
17 Wilds, G. J. op. cit. 
