Íslenskar landbúnaðarrannsóknir - 01.03.1970, Blaðsíða 40

38 ÍSLENZKAR LANDBÚNAÐARRANNSÓKNIR
whole material and transferred to a work
tape.
This selection was carried out in such a
way that if a mating was found where the
genotypes of both parents at this locus
were known, the whole card was transferr-
ed to the work tape and kept there in the
sarne way as on the original tape, i.e. in
20 packed words and 25 packed cards per
each 512 word block.
Similarly all cards with both genotypes
at the B-locus known prior to mating were
selected out from the whole material and
transferred to a work tape and the same
was finally repeated with respect to the S-
locus.
All information about segregation ratios
was then obtained from the selected cards
on the work tape.
CHAPTER V
Observed segregation at the A-locus
A. OBSERVED COLOURS
Altogether 21 different genotypes are pos-
sible at locus A, and 441 different types
of matings are therefore possible by mat-
ing all genotypes of sires to all genotvpes
of dams.
From the experiments and the collected
field records information is available on
111 of these matings, and the results of
these are shown in table 9. In the table
all lambs with known colour have been in-
cluded.
It has been pointed out before that the
patterns manifest themselves independent-
ly of the type of pigment. Each pair of
main colours with the same pattern is
therefore given as one group in table 9.
Altogether 3452 lambs with known colour
are included in table 9. The most frequent
colour is white with 1690 larnbs. Next
comes the black-|-brown group with 741
lambs and thereafter grey-)-greybrown, 631
lambs.
Black or brown badgerface-mouflon has
occurred very rarely and has only been
present in 7 larnbs in table 9. It should
be noted at this stage, however, that tlie
expected number of lambs of this colour
from the matings given in table 9 was 4.75
lambs, as only 19 lambs were obtained
from matings which could produce this
colour and the probability for it occurring
was 0.25 in each case. This important col-
our with respect to the dominance rela-
tionship between the badgerface ancl mou-
flon patterns has therefore occurred with
the expected frequency (x2i = 1.422;
0.30>P>0.20).
This result is therefore in full agreement
with the view that the two patterns,
badgerface and mouflon, will both be ex-
pressed when they occur together in the
same anirnal. Roberts and White (1930 a)
found the badgerface pattern to be domin-
ant to the mouflon pattern, while Berge
(1958, 1964 a) found the badgerface pat-
tern to be recessive to the mouflon pattern
and neither of these authors reported the
simultaneous occurence of the two patterns
in the same animal.
B. UNEXPECTED COLOURS
As table 9 shows, 23 lambs out of the 3452,
or 0.67 per cent, show colours other than
expected. As deviation from expected col-
ours are more likely to be discovered in