Florida Agricultural Experiment Station


judging the data of Table 10 as a whole, there can be little
doubt that the hypothesis of duplicate genes with deficiencies
of recessive gametes and zygotes is correct. It is also indicated
that the calculated values of q, q', and w which are measures
of those deficiencies are not greatly in error, at least in their
resultant.
 Records of yellow seedlings in the other three crosses are
 available only for the F2 and F3 generations. These data are
 sufficient only to set limits on w and to approximate q and q'.
 In cross 13 x 14 there were 82 F2 seedlings of which 64 green
 plants were grown to maturity and tested for segregation with
 4,479 F3 seedlings. By the formulae given above for a dihybrid,
 maximum w is 0.91 and minimum w is 0.84. Taking the maxi-
 mum value of w, q = 1 and q' = 0.57. Taking the minimum
 value of w, q = q' 0.78.
 In cross 3 x 8 there were 212 F2 seedlings from three F1 plants
of which 198 were grown to maturity and tested for segregation
with 13,781 F3 seedlings. Maximum w is 0.727 and minimum
w is 0.723. For minimum w, q = q' = 1.08. In this cross
the proportion of segregating plants is slightly in excess of the
expected proportion with q = q' = 1. There is no evidence
of deficiency in q or q'.
 In cross 13 x 8 there were 146 F2 seedlings of which only
two were yellow. However, the occurrence of yellow plants
among 6,174 F3 seedlings from 121 F2 plants is very similar to
that of the previous cross. The unusual F, result prevents
any reasonable determinations of limits on w as in previous
crosses. The proportion of segregating F2 plants is very close
to that expected with q = q' = 1. There is no evidence of
deficiency in q or q'. Two estimates of w have been made from
the ratios of green to yellow plants in the F3 derived from the
segregating F2 plants and in the total Fs. In these two cases
the proportions of yellow plants are 0.73 and 0.74 of that ex-
pected with q, q', and w equal to one. This deficiency must
be largely ascribed to w, and the ratios of yellow plants obtained
to the numbers expected with a hypothesis of w equal to one
may be considered estimates of w.
 Values of q, q', and w obtained in the first two crosses are
quite similar. These crosses involve runner strain No. 14 crossed
with the Spanish strains No. 1 and No. 13. The latter two
crosses also behaved similarly but different from the first two.
They involve runner strain No. 8 crossed with Spanish strains