Increased
efficiency
of
interspecific
hybrids
by
embryo
rescue
in
crosses
between
L
.
esculentum
and
L
.
peruvianum
Sánchez
-
Donaire
1
,
A
.
,
Encina
2
,
C
.
L
.
,
Cuartero
2
,
J
.
,
Guerra
-
Sanz
1
,
J
.
M
.
1)
C
.
I
.
F
.
H
.
Almería
.
-
P
.
O
.
Box
91,
EL
EJIDO
(Almería
.
-
Spain)
2)
La
Mayora,
CSIC
.
Algarrobo
-
Costa
.
-
Malaga
.
-
Spain
e
-
mail:
jmguerra@arrakis
.
es
Procedures
for
hybridization
between
domestic
tomato
varieties
and
L
.
peruvianum
have
to
be
improved
to
make
easier
use
of
the
great
diversity
of
genes
belonging
to
peruviamun
complex
.
Although
procedures
to
avoid
incompatibility
barriers
have
been
described,
mainly
using
in
vitro
culture
of
the
embryos
and
ovules
(Imanishi,
1991;
LanZhuang
&
Adachi,
1991;
Imanishi
et
al
.
,
1996;
Doganlar
et
al
.
,
1997;
Sacks
et
al
.
,
1998),
the
number
of
hybrid
plants
obtained
have
been
always
low
.
Therefore
the
objective
of
the
present
work
was
to
improve
the
methodology
to
get
a
high
number
of
hybrid
plants
by
embryo
rescue
following
crosses
between
L
.
esculentum
and
L
.
peruvianum
.
Two
accessions
of
L
.
peruvianum
(LA
1278
and
LA
98)
from
TGRC
(Dr
.
R
.
Chetelat,
Univ
.
Of
California,
Davis,
USA),
and
two
varieties
of
L
.
esculentum
(Muchamiel
and
Moneymaker)
from
"La
Mayora"
(Dr
.
J
.
Cuartero)
were
used
.
Plants
from
those
genotypes
have
been
grown
under
greenhouse
conditions
and
kept
until
flowering
and
harvesting
under
optimal
nutritional
conditions
.
Manual
crosses
have
been
carried
out
using
L
peruvianum
as
pollen
donor
and
L
.
esculentum
as
pollen
receptor
.
Pollen
from
each
genotype
was
collected
by
breaking
and
mixing
at
least
ten
mature
anther
cones
in
a
Petri
dish
.
The
flower
of
the
female
partner
was
emasculated
just
before
anthesis
.
Pollination
was
made
by
rubbing
the
pollen
obtained
on
the
surface
of
the
stigma
of
the
emasculated
flower
.
At
least
four
fruits
of
each
cross
were
harvested
between
30
to
45
days
after
pollination
.
The
fruits
were
surface
-
sterilized
by
10
minutes
immersion
in
97%
ethanol,
left
to
dry
out
inside
the
flow
bench
and
dissected
under
sterile
conditions
.
Embryos
were
selected,
only
those
cultures
that
were
bigger,
green
(the
majority
appeared
white)
and
with
plump
appearance
were
chosen
for
culture
.
A
superficial
cut
was
done
with
the
scalpel
on
the
embryo
coat
in
the
zone
of
the
cotyledons
and
passed
immediately
into
Petri
dishes
containing
OMS
medium
(Finer,
1987):
MS
(Murashige
&
Skoog,
1962)
mineral
salts
and