Inheritance
of
resistance
to
race
1
of
Pseudomonas
syringae
pv
.
tomato
in
line
LCHG
177
Sotirova,
V
1
.
,
Bogatsevska,
N
2
.
and
Vulkova,
Zl
1
1
Institute
of
Genetics,
BAS,
1113
Sofia,
Bulgaria
2
Institute
of
Plant
Protection,
2230
Kostinbrod,
Bulgaria
Bacterial
speck,
caused
by
Pseudomonas
syringae
pv
.
tomato
(Pst),
is
a
widespread
disease
in
various
areas
of
the
world
(Pitblado
and
Kerr,
1980;
Goode
and
Sasser,
1980;
Bogatsevska,
1980;
Gitaitis
et
al
.
,
1992)
.
The
investigation
into
the
race
status
of
Pst
isolates
was
reported
by
Lawton
and
MacNeil
(1986),
Bogatsevska
et
al
.
(1989),
Buonario
et
al
.
(1996)
.
There
are
two
known
races
of
Pst
–
race
0
and
race
1
.
Resistance
to
Pst
is
genetically
well
characterized
in
the
Canadian
lines
ONT
7710,
ONT
7611
and
ONT
782
.
According
to
Pitblado
and
Kerr
(1980)
resistance
in
these
lines
was
controlled
by
one
dominant
gene
designated
as
Pto
(Kerr,
1982)
.
The
gene
is
localized
on
chromosome
5
at
position
30
(Pitblado
and
MacNeil,
1984)
.
The
line
LCHG
177
was
developed
from
a
BC2
of
(
L
.
esculentum
–
L
.
chilense
LA
456
–
L
.
peruvianum
PI
127829)
x
L
.
hirsutum
f
.
glabratum
LA
407
accompanied
by
selection
of
resistant
plants
to
race
1
of
Pst
.
The
material
discussed
presents
the
following:
1)
.
To
determine
the
mode
of
inheritance
to
race
1
of
Pst
found
in
the
line
LCHG
177
.
2)
.
Test
of
allelism
for
gene
in
line
LCHG
177
and
gene
Pto
responsible
for
resistance
to
bacterial
speck
in
Canadian
line
ONT
7710
.
A
study
of
F1
progenies
of
crosses
Ideal
x
LCHG
177
and
Ace
x
LCHG
177
indicated
that
the
resistance
is
dominant
.
F2
segregating
progenies
consisted
of
resistant
and
susceptible
plants
in
approximately
a
3:1
ratio
indicating
a
single
dominant
gene
for
resistance
.
A
segregation
ratio
of
one
resistant
to
one
susceptible
plant
in
BC1
of
the
susceptible
parent
confirm
the
hypothesis
that
resistance
to
race
1
of
Pst
in
line
LCHG
177
is
controlled
by
a
single
dominant
gene
(Table1)
Table
1
.
Segregation
of
resistance
to
race
1
of
Pseudomonas
syringae
pv
.
tomato
in
LCHG
177
Segregation
Observed
Expected
Progenies
R
S
R
S
c
2
P>
Ideal
0
17
Ace
0
25
LCHG
177
22
0
F1
Ideal
x
LCHG
177
31
0
F1
Ace
x
LCHG
177
28
0
F2
Ideal
x
LCHG
177
269
93
271
.
5
90
.
5
0
.
092
0
.
50>P>0
.
80
F2
Ace
x
LCHG
177
164
66
172
.
5
57
.
5
1
.
674
0
.
05>P>0
.
20
BC1
(IdealxLCHG177)xIdeal
27
36
31
.
5
31
.
5
1
.
284
0
.
20>P>0
.
50
BC1
(AcexLCHG177)xAce
38
45
41
.
5
41
.
5
0
.
59
0
.
20>P>0
.
50
R
-
resistant;
S
-
susceptible
The
allelism
study
between
Canadian
