June 23, X923 
Rust Resistance in a Marquis-Kota Cross 
1009 
Table X. —Distribution of Fq normal awnless (A) and bearded (B) plants and dwarf 
awnless (DA) and bearded (DB) plants, classified according to their reaction to Form 
XIX in relation to spike characteristics of F2 plants 
F" plant type. 
A. 
B. 
DA. 
DB. 
Total 
F3 reaction to Form XIX. 
IR. 
HR. 
H. 
HS. 
IS. 
28 
35 
78 
28 
142 
10 
12 
23 
II 
46 
I 
0 
12 
I 
19 
0 
2 
3 
I 
5 
39 
49 
II6 
41 
212 
Table XI. —Distribution of F^ normal awnless (A) and bearded {B) plants and dwarf 
awnless {DA) and bearded {DB) plants, classified according to their reaction to Form 
XXVII in relation to spike characteristics of F2 plants 
Three times as many awnless families as bearded were expected. 
The fact that there were about three times as many awnless as bearded 
families in each of the groups classified according to reaction to both 
biologic forms seems very convincing proof that the factors which govern 
susceptibility or resistance to either Form XIX or Form XXVII are 
inherited separately from the factors which govern the presence or 
absence of awn development. 
To Form XXVII the reaction of the F3 families from the dwarf types 
seems very similar to that obtained from normal plants. For Form 
XIX, however, the percentage of dwarf plants which were as resistant 
as Marquis and which were placed in the IR group is very small and 
certainly much less than the percentage of similar families from the 
normal plants. 
In a somewhat similar manner the relation between average length 
of seed of the Fg plants and the reaction of these plants to Forms XIX 
and XXVII was determined, as shown in Tables XII and XIII. 
