Íslenskar landbúnaðarrannsóknir - 01.03.1970, Blaðsíða 102

1 00 ÍSLENZKAR LANDBUNAÐARRANNSÓKNIR
14 the recombination of the genes in ques-
tion. Thus there is no indication of link-
age from this particular sample, but one
can naturally not claim that the results
eliminate the possibility of linkage. The
estimated recombination percentage with
its standard deviation is 46.67 ±9.11,
which gives the lower 95 per cent limits
of the recombination percentage as 28.81
per cent, so it can be said with confidence
that there is at least no close linkage be-
tween the two loci.
For linkage between loci A and C in-
formation was available on the origin of
both alleles of only S sires heterozygous at
both loci. They left altogether 8 progeny
when mated to homozygous S2S2-ewes
which carried other alleles at the A-locus
than the sires. Of the progeny, 4 showed
the parental combination and 4 the recom-
bination of the genes in question. This
very scanty evidence thus does not indicate
any linkage between loci A and S either.
Scattered information about linkage can
be obtained from the progeny of individual
TABLE 60
Effect of colour genotypes of ewes at loci B and S on variation in number
of larnbs per ewe lambing. Tiao year old ewes
Source of variation DF SS MS F
1. Locus B
Between farm-years, el, genotypes 109 35.1313 0.3223 1.62**
Between genotypes, el. farm-years 1 0.0791 0.0791 0.40
Interaction farm-years X genotypes 37 9.0259 0.2439 1.22
Error 313 62.3228 0.1991
2. Locus S
Between farm-years, el. genotypes 109 35.7120 0.3276 1.64**
Between genotypes, el. farm-years 1 0.0982 0.0982 0.49
Interaction farm-years x genotypes 43 9.8086 0.2281 1.14
Error 307 61.5210 0.2004
and B, knowledge is available about the
origin of both alleles among only 5 sires
lieterozygous at both loci. These sires left
altogether 30 progeny when mated to ewes
whicli were homozygous B2B2 and which
carried other alleles than those found in
the sire at the A-locus. Of these S0 progeny,
16 showed the parental combination and
TABLE 59
Least squares estimates of effect of colour
genotypes of ewes at loci B and S on num-
ber of lambs per ewe lambing. Two year
old ewes
Genotype No. of Estimated
of ewe lambings deviations
Bi- 372 -0.02
B2B2 89 0.02
Si- 375 -0.02
S2S2 86 0.02
**) P<0.01