Hayes and Garber - Cucurbit Breeding

100 BREEDING CROP PLANTS
was thought possible that minor modifying factors were sometimes
present which influenced the degree of fruitfulness of the
lateral florets.
FIG. 23. Individual spikes of Fi generation of cross of Svanhals X Manchuria
representing phenotypic progeny classes in which the lemmas of the lateral
florets are rounded and awnless. From left to right: The two-rowed class which
will breed true in /%; low fertility class which will give two-rowed, low fertility
and intermedium in F 3 ;
intermedium which will breed true for intermedium
habit in F.?. (After Harlan and Hayes, 1920.)
Crosses between intermedium and six-rowed forms gave
intermediates of high fruitfulness in F\ and a ratio of six-rowed to
intermediates in F% which indicated a single factor difference.
Intermedium forms crossed with two-rowed gave awnless forms