Development
of
a
large
fruited
tomato
with
a
high
level
of
resistance
to
bacterial
w
(
Ralstonia
solanacearum
)
.
Scott,
J
.
W
.
1
,
Jones,
J
.
B
.
2
,
and
Somodi
G
.
C
.
1
1
University
of
Florida,
IFAS,
Gulf
Coast
Research
&
Education
Center,
Bradenton,
FL
34203
2
University
of
Florida,
Department
of
Plant
Pathology,
PO
Box
110680,
Gainesville,
FL
32611
-
0680
Bacterial
wilt
is
a
serious
disease
problem
in
many
humid,
tropical
growing
areas
around
the
world
.
Unfortunately
breeding
for
resistance
has
been
difficult
for
a
number
of
reasons
including
different
races,
complex
resistances,
and
environmental
effects
on
disease
expression
that
have
limited
the
development
of
artificial
se
ilt
edling
screening
techniques
.
here
have
also
been
reports
of
associations
of
resistance
with
small
fruit
size
(Acosta
et
al
.
,
e
e
had
r
its
rous
selections
over
the
years
with
large
fruit
size
turned
out
to
ave
less
resistance
than
that
of
Hawaii
7997
.
ttempts
were
made
to
break
the
apparent
linkage
of
a
hypothetical
fruit
size
gene
with
a
selecting
resultant
F
2
rogeny
for
resistance
and
larger
fruit
.
Eight
breeding
lines
were
originally
crossed
with
from
this
ne
was
crossed
to
Fla
.
7834,
a
large
-
fruited
breeding
line
and
progeny
from
the
F
2
and
rge
and
designated
Fla
.
8109
and
Fla
.
8109B
.
ansplanting
to
the
field,
the
plants
30
days
past
the
cotyledon
stage
were
inoculated
with
the
pathogen
in
Todd
®
planter
flats
.
Each
plant
received
5
mL
of
a
suspension
containing
10
7
cfu/mL
of
the
bacteria
.
Twenty
-
two
days
after
the
inoculation
the
plants
in
the
field
were
scored
for
disease
symptoms
that
included
death,
stunting,
wilting,
and/or
chlorosis
leading
to
browning
of
foliage
.
Plants
were
checked
later
in
the
season
but
there
was
no
further
disease
development
.
In
Spring
2003
Fla
.
8109,
Fla
.
8109B,
Neptune,
Horizon,
and
Sanibel
were
grown
in
a
completely
randomized
design
with
two
replications
and
4
to
6
plants
per
plot
.
Fruit
reaching
the
breaker
or
beyond
stage
were
harvested
three
times
at
weekly
intervals
.
For
each
plot,
fruit
were
counted
and
weighed
in
order
to
obtain
yield
and
fruit
size
information
.
T
1964)
although
other
researchers
did
not
find
such
an
association
(Danesh
et
al
.
,
1994;
Monma
and
Sakata,
1993)
.
Some
of
the
most
widely
adapted
sources
of
resistance
hav
been
a
series
of
lines
from
Hawaii,
bred
by
Dr
.
J
.
C
.
Gilbert
in
the
1960’s
and
1970’s
.
In
our
breeding
program
we
use
mainly
Hawaii
7997
as
a
source
of
resistance,
but
we
hav
great
difficulty
developing
large
-
fruited
types
with
resistance
comparable
to
Hawaii
7997
.
Ou
bacterial
wilt
resistant
release
‘Neptune’,
tested
as
Fla
.
7421,
had
medium
-
large
fruit
but
resistance
was
less
than
that
of
Hawaii
7997
and
not
as
broadly
adapted
(Scott
et
al
.
,
1995;
Wang
et
al
.
,
1998)
.
Nume
h
A
bacterial
wilt
resistance
gene
by
crossing
breeding
lines
with
medium
-
large
fruit
and
intermediate
resistance
back
to
Hawaii
7997
in
1996
and
then
re
-
p
Hawaii
7997
.
From
this
original
crossing
a
F
5
line
was
selected
that
had
a
high
level
of
resistance,
but
only
a
moderate
fruit
size
increase
over
Hawaii
7997
.
A
selection
li
further
generations
were
screened
for
bacterial
wilt
resistance
and
fruit
size
.
This
time
a
la
fruited
F
2
was
selected
and
screening
and
selection
continued
until
the
F
6
generation
.
In
the
F
6,
two
selections
were
made
In
Summer
2002
these
two
lines
and
nine
others
were
grown
in
a
completely
randomized
block
design
with
3
blocks
and
10
plants
per
plot
.
Three
days
before
tr
No navigation control above? Click here!