200
‘
G.W. WohIfaräh
of
production traits and family selection programs (Moav et
1976).
Use
of
brood
stock
with
appropriate
electrophoretid
markers enables the production of different identifiable genetid
groups from one multiple spawn° Several full sih within half sib
may
thus
be_
spawned
simultanously
is
one
pond.
_Teohnioally this enables a reduction in the number
of
spawning
and
nursing ponds required for a given number of genetic-groups
to be
It also means that these
test
groups
common
environment from hatehing till the end of the test. This
technique was applied for testing
differences
in
growth
among
families
of
the Dor—7O
line of
the European oarp as well
as
different crossbred
families
between
European
and
Chinese
oarp
(Brody et al,,
The results showed a large variation
in
growth among the progenies of different pairs of Dor—7O andja
smaller
among
,crossbred
families.
The mean of the
orossbreds exoeeded that of
the
European
purebreds,
but
better European purebreds grew as well as the better crossbreds.
A
progeny
testing
program
of
this
type
enables
isolating
,
individuals
with
ahigh
specific
oomhining
ability.
Its
practical
application
is
however
limited
to
the
use
of
individual
pairs.
Testing
full
sib
families
in this manner
enables
isolating groups of
fish
of
two
distinct
genotypeë,
which,_ when
interbred,
generate
progenies
with
an
impr0Vëd
growth (Brody et al.,
1981).
It may
be
used
for
a
reoiprocal
recurrent selection. None of these methods have been
applied in praçtioal schemes for the genetic improvement of« the
or
any
other fish.
'
,
;E —…
‘
.
'
…
ÎWDefforts were carried out, aimed at improving
speqial
based
°n *
…bêtweendamesbicaüed EuropeancaïP and
Gä_ïP ,
but
of
slow
growth
,,
‘
_
_
Tolerance to
-
It
was
attemPted to improve the growth rate of common oarp
Bt
in order to increase yields in north eastern
U-5ff5-…R(KirPiChnikwïr
“Iähe method
«was
crossingzdomEsticabed European
resiëtat
strain, from;
Amur (on the border between Siberia and
Menhuria)» wThtiza QWBS ,
&
°f
and
for several qenerations, and gave
SEVEÏBl
beïmEd
pends in
areas
in
north—eastern
indicate that Ropsha
faster
than
domestioated European carp
et ai…, 1970; ZODDVä
and
ShatnoVa, 1970). In addition to its cold—resistance,
RDP5hB
oarp
is
more
resistant
to
and air bladder
disease
than
domestioated' European
1971):
_Baplacemant… Qf
,
car? «decreased
,1ncaençe
thedeaaee
:
"
…
-