Backcrossing
¥
C x A
¥
ø
¥
F
1
x A
¥
ø
¥
B
1
x A
¥
ø
¥
B
2
x A
¥
ø
¥
B
3
x B
3
¥
¥
ø
¥
B
3
-F
2
x B
3
-F
2
¥
¥
ø
¥
B
3
-F
3
Proportion
Resistant
all
1/4
1/4
1/4
1/16
all