15
RESEARCH
NOTES
TGC
REPORT
No
.
31,
1981
We
tried
to
check
different
testing
methods
in
order
to
study
the
influence
of
low
night
temperature
on
pollen
maturity
using
42
F2
hybrids
between
resistant
and
susceptible
varieties
.
We
have
used
as
a
source
of
low
temperature
adaptation
Sub
Arctic
Delighted
crossed
with
greenhouse
and
field
varieties
.
The
hybrids
ware
grown
in
a
plastic
greenhouse
in
the
spring
and
fall
.
The
night
temperature
during
the
opening
up
of
the
first
3
inflorescences
was
5
-
10oC
.
We
compared
the
rate
of
plant
growth
with
the
number
of
points
given
for
the
blossom
and
fruit
set
ability
(N
.
Musat
method)
.
We
have
also
analysed
the
pollen
viability
with
acetocamine
and
germination
in
vitro
(sucrose
15%)
.
We
have
also
tried
to
compare
our
results
with
seed
germination
in
high
osmotic
pressure
solution
-
KNO3,
1%
.
Some
seeds
of
two
lines
germinated
in
60
hours
but
most
lines
and
hybrids
were
inhibited
and
germinated
after
5
-
8
days
.
We
have
found
a
significant
relation
between
the
rate
of
growth
and
the
number
of
points
accorded
for
blossom
and
good
fruit
-
set
ability
for
most
of
the
hybrids
.
The
acetocarmine
test
was
not
significant,
but
the
germination
of
the
pollen
in
vitro
was
much
more
conclusive
and
related
with
the
fruit
setting
at
low
tempera
-
tures
.
The
germination
of
seeds
in
1%
solution
of
KNO3
can
be
used
as
an
efficient
method
of
selection
for
cold
set
ability
or
generally
for
non
-
favorable
conditions,
though
it
is
not
strictly
related
with
low
temperature
adaptation
.
It
seems
to
us
that
cold
resistance
is
not
absolutely
related
with
low
temperature
fruit
setting
and
may
be
under
control
of
different
groups
of
genes
.
Rao,
R
.
N
.
and
Panuganti
N
.
Rao
Pachytene
Details
on
the
frequency
and
chromosome
pairing
in
a
sesqui
-
distribution
of
partner
exchanges
for
diploid
Lycopersicon
esculentum
(4n)
the
various
chromosome
sets
in
the
x
L
.
peruvianum
var
.
glandulosum
triploid
hybrid
L
.
esculentum
cv
.
(2n)
.
Marglobe
(4n)
x
L
.
peruvianum
var
.
glandulosum
(2n)
were
studied
in
comparison
with
the
observations
of
a
similar
nature
in
the
autotetraploid
L
.
esculentum
var
.
Marglobe
to
a
