Inheritance of Rest Period of Seeds in the Peanut


heritance studies of yellow seedlings have been made principally
in four crosses involving Spanish and runner strains. Data
of the cross 1 x 14 which was studied most extensively are
presented in Table 10. It soon became apparent that very few
families appeared in this or other crosses with ratios as low
as 3:1. Consequently a few F3 progenies were selected because
of low ratios in seedling progeny tests with the expectation that
only monohybrid plants would be included. These were con-
tinued another generation and seedling tests were made from
F4 plants. Ratios of true and segregating F4 families and green
and yellow F5 seedlings are shown in the last two entries of
the table. The deficiency of yellows in the F5 test is too great
to be ascribed to chance, nor can it be explained by differential
germination since the segregating families germinated equally
with their sibs. Since the deficiency appeared in monohybrid
families, it could not be due to linkage of duplicate genes. Other
possible causes, e. g. abnormal behavior at meiosis, must become
evident in unequal numbers of effective gametes or in differential
viability of zygotes.
 An attempt was made to determine as closely as possible
gametic ratios of both sexes and differential viability of zygotes.
It was assumed after a preliminary inspection of the data that
gametes containing one or more dominant genes were produced
in equal numbers and were equally viable. The ratio of fully
recessive gametes to those of any one dominant class was defined
as q. The gametic proportion for one sex of the monohybrid
was then written
 1 q
 + 1
 1+q 1+q
and for the dihybrid
 1 1 1 q
 -- + -- + = 1.
 3+q 3+q 3+q 3+q

 Identical equations with q' served for the other sex in both
 cases. It was further assumed that zygotes with one or more
 dominant genes were equally viable and that the ratio of viabil-
 ities of dominant and recessive zygotes was (1:w).
 Defining:
 T = recorded number of dominant progeny breeding true,
 S = recorded number of dominant progeny segregating,
 Y = recorded number of recessive progeny,