Reduction
of
fruit
growth
results
in
lower
incidence
of
blossom
-
end
rot
in
tomato
van
der
Knaap,
E
.
and
Tanksley,
S
.
D
.
Departments
of
Plant
Breeding
and
Plant
Biology
Cornell
University,
Ithaca
NY,
14853
Blossom
-
end
rot
(BER)
in
tomato
is
associated
with
a
localized
calcium
deficiency
in
the
distal
portion
(blossom
end)
of
the
fruit
.
BER
is
induced
by
poor
watering
conditions;
either
too
much
or
too
little
water
.
However,
BER
is
not
the
result
of
a
single
factor,
but
from
the
interaction
of
several
conditions
such
as
light,
temperature,
relative
humidity
and
nutrient
status,
with
the
genotype
(Ho
et
al
.
,
1993;
Mutsumi
and
Taikichi,
1995a,b,c)
.
During
the
course
of
an
unrelated
experiment,
measurements
of
individual
fruits
of
TA491
(Sun
1642)
were
taken
at
regular
intervals
from
the
time
of
pollination
to
ripe
fruit
.
We
found
that
fruits
that
were
to
develop
BER
grew
faster
following
pollination,
than
fruits
that
were
not
developing
BER
(Figure
1)
.
Furthermore,
fruits
of
plants
treated
with
Bonzi
(growth
retardant;
inhibitor
of
GA
biosynthesis)
developed
less
BER
than
fruits
of
non
-
treated
plants
(14%
vs
81%;
Table
1)
.
However,
Bonzi
treatment
resulted
in
reduced
fruit
set
compared
to
non
-
treated
plants
(70%
vs
98%;
Table
1)
.
The
results
suggest
that
reduced
fruit
growth
in
TA491
may
prevent
BER
.
At
this
time,
it
is
unclear
whether
reduced
fruit
growth
is
accomplished
directly
by
changes
in
environmental
conditions
(temperature,
nutrient
status
or
relative
humidity)
and/or
indirectly
by
poor
seed
set
.
Poor
seed
set
may
be
the
consequence
of
reduced
levels
of
GA
.
Table
1
.
Incidence
of
BER
and
fruit
set
in
Bonzi
-
treated
vs
non
-
treated
TA491
fruit
.
incidence
of
BER
fruit
set
Bonzi
treatment
2
out
of
14
14
out
of
20
No
treatment
44
out
of
53
53
out
of
54
Literature
cited:
Ho,
L
.
C
.
,
Belda,
R
.
,
Brown,
M
.
,
Andrews,
J
.
,
Adams,
P
.
(1993)
J
of
Exp
Botany
44,
509
-
518
.
Mutsumi,
W
.
,
and
Taikichi,
T
.
(1995a)
Environmental
Control
in
Biology
33,
7
-
14
.
Mutsumi,
W
.
,
and
Taikichi,
T
.
(1995b)
Environmental
Control
in
Biology
33,
15
-
21
.
Mutsumi,
W
.
,
and
Taikichi,
T
.
(1995c)
Environmental
Control
in
Biology
33,
49
-
57
.
