Butler, L.
It has been pointed out that a lethal gene such as Wo, will disturb the monogenic ratios of any gens with which it is closely linked, and that the amount of disturbance will depend on the recombination value and the linkage phase. A good example of this was encountered last year when I attempted to place Cu in group 2. The cross was:
P\1 m d p aw + Wo + + + + Cu +
_____________ X ____________
m d p aw + + + + + + Cu +
F1 m d p aw + Wo m d p aw + +
_____________ and ____________
+ + + + Cu + + + +v+ Cu +
F2 Wo Cu + + 333 + Cu + + 239 (170) 385
Wo Cu + d 55 + Cu + d 10 (23) 53
Wo Cu aw + 7 + Cu aw + 0 (2) 4
Wo Cu aw d 40 + Cu aw d 0 (6) 13
Wo + + + 2 + + + + 0 (8) 19
Wo + + d 0 + + + d 0 (0) 1
Wo + aw + 0 + + aw + 0 (18) 42
Wo + aw d 0 + + aw d 1 (22) 50
The second and fourth columns of figures show the large differences brought
about by the presence of Wo, and this is emphasized by the figures in brackets
which show the expected on the basis of the segregation of the wo^+ F1. The
monogenic segregations are:
F1 Wo F1 wo^+
Wo : wo 437 : 250
Cu : cu 684 : 3 455 : 112
Aw : aw 639 : 48 458 : 109
D : d 581 : 106 450 : 117
The number of recessives is short in both F2's but in the Wo F2 the recessives
are drastically reduced, especially if they are close to Wo.