Oct. 1, 1924 
Inheritance of Earliness in Wheat 
347 
The recessive late group of the F 2 
remained late in the F 3 , tending to 
confirm the presence of only one pair 
of factors for earliness as contrasted 
with lateness. Further evidence of 
this view was furnished by the fact that 
more than one-half of the F 3 population 
apparently was homozygous for earli¬ 
ness. 
These studies indicate that earliness 
or lateness in wheat is a definitely 
heritable character, and reports by 
various investigators show it to vary 
in complexity in different combinations. 
Within the common wheat group the 
character for earliness in winter (habit) 
X spring (habit) varieties apparently 
is more complex than in crosses be¬ 
tween two spring (habit) varieties. 
It is possible to determine progeny 
rows homozygous for earliness in F 3 
and subsequent generations of hybrids 
by the time required for them to pass 
through the heading stage. This con¬ 
clusion is based on the assumption that 
pure-line rows pass through the heading 
stage in a time approximately equal to 
that of pure-line parent varieties. 
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