The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source
site maintained by the Florida
Cooperative Extension Service.
Copyright 2005, Board of Trustees, University
Ft. Pierce ARC Research Report RL-1977-3 June 1977
__. Behavior of tomato lines, selected for resistance to o EgL/----.
bacterial wilt, in a field infested with the pat g LIP RY
R. M. Sonoda 2/ JAN 1978
ABSTRACT .F.A.S. Univ. of Flori,4
One hundred twenty one lines of tomatoes were screened in
tests in a field naturally infested with Pseudomonas solanacearum E.
F. Smith, incitant of southern bacterial wilt. Between 58 and 99%
of commercial Florida varieties, Walter, Florida MH-1 and Floradel
were killed by the pathogen in the three tests. From 7 to 19% of
the plants of the varieties Venus and Saturn, and the primitive
Lycopersicon esculentum line PI 126408 were killed. Plants resis-
tant to the P. solanacearum present in Hawaii soils were as sus-
ceptible as the Florida commercial varieties to the P. solanacearum
indigenous to the Agricultural Research Center, Fort-Pierce. A few
of the tomato lines obtained from crosses made by the late J. M.
Walter were slightly less susceptible than commercial Florida lines.
Venus and Saturn did not have satisfactory horticultural character-
SSouthern bacterial wilt incited by Pseudomonas solanacearum E.
F. Smith is a world-wide disease of great economic importance on
tomatoes and many other crops (1). Although death of plants over
an entire tomato field can occur in Florida, the disease has gener-
ally been restricted to localized areas of fields. All commercial
tomato varieties currently grown in Florida are susceptible to the
disease. Resistant varieties or sources of resistance have been
reported from Brazil, Ceylon Japan, Philippines, West Indies,
Hawaii and North Carolina (3) and from Florida (R. E. Stall, Univer-
sity of Florida, IFAS, personal communication).
Loss of resistance to the disease with increased temperatures
has been reported with some of the resistant varieties (2, 3).
Breakdown in resistance due to the presence of different strains of
the bacteria has also been reported (2). The objective of this study
was to determine the survivability of plants with different sources
of resistance in soil naturally infested with the pathogen.
I/ Associate Plant Pathologist, University of Florida Institute of
Food and Agricultural Sciences, Agricultural Research Center,
Materials and Methods
Tomato lines crossed and selected by the late J. M. Walter for
resistance to P. solanacearum and selected further for horticultural
characteristic? by J. W. Strobel and P. Crill (all formerly with the
University of Florida, AREC Bradenton) were obtained from P. Crill.
A selection of PI 126408 was obtained from R. E. Stall, University
of Florida, Gainesville). Seven lines from Hawaii were obtained from
J. C. Gilbert, University of Hawaii. Saturn and Venus, resistant
varieties, bred in North Carolina, were obtained from R. E, Stall.
Saturn seed were also obtained from the Dessert Seed Company. PI
281666 and PI 281868, two lines with high tomatine content were ob-
tained from the USDA Northern regional laboratory, Ames, Iowa.
Seeds of the tomato lines were sown in Jiffy Mix Plus (Cornell
Peat-lite type mix with a controlled release fertilizer added) in
plastic multipot flats in the greenhouse. When seedlings were two
weeks old they were thinned to one seedling per cell in the multipots
and transferred to outdoor benches for two more weeks before trans-
planting to the field.
The seedlings were transplanted into soil infested with P.
solanacearum at the Agricultural Research Center, Fort Pierce.
Three plantings were made in a field where 86% of Walter tomato
plants had been killed by bacterial wilt in a planting made in the
fall of 1973. All three plantings consisted of five replications
of six plants each in a randomized complete block design. Seedlings
with Jiffy Mix Plus attached to their roots were placed in holes on
raised beds in the field. Test 1 transplanted to the field on
3-8-74, consisted of 26 lines obtained from P. Crill,; Saturn,
Floradel and Florida MH-1. Test 2 transplanted on 5-27-74, consisted
of 37 lines from P. Crill, PI 126408, PI 281866, PI 281868, seven
lines from Hawaii, Venus, Walter and Florida MH-1, Test 3 transplanted
on 7-30-74, consisted of 46 lines from P. Crill, PI 126408, Saturn,
Walter, and Florida MH-1. In Tests 2 and 3, each hole was drenched
with a cup of 2,500 ppm Difolatan 4F plus 7.200 ppm Start-Rite ferti-
lizer (10-52-8) mix. After the roots and base of the plant were
covered with soil, the area around the base of the plant was drenched
with 1/2 cup of the fungicide-fertilizer mixture. The fungicide
Difolatan was used to reduce the incidence of transplant damp-off (4).
Between 20 and 55% of the plants in each line in Test 1 were
killed by Pythium phanidermatum or Rhizoctonia solani in the first
10 days after planting. Wilting of plants due to P. solanacearum
- 3 -
was noticed about 3 weeks after planting. Disease incidence was not
uniform throughout the plot as there were significant differences in
numbers of wilted plants between replicates of some of the accessions.
Of the plants surviving damp-off, 58% of Floradel and 84% of
Florida MH-1 were killed by P. solanacearum (Table 1). Only 11% of
Saturn plants were killed by the pathogen. Two of Dr. J. M. Walter's
lines, 708-6 and 701-14 lost 21 and 33%, respectively of their plants.
No significant difference was obtained in survival percent between
any of the lines.
About 12% of the plants in Test 2 were killed by damp-off. Of
the survivors, Venus and PI 126408 were the most resistant to bacter-
ial wilt, (Table 2). The Hawaii lines 7755, 7959, 7843 x Saturn,
BWN-14, BWN-13, BWN-12 and BWN-21 were highly susceptible.
In Test 3 (Table 3) about 15% of the plants were killed by
damp-off. Saturn and PI 126408 lost the fewest plants to bacterial
Both Venus and Saturn were highly tolerant to the strain of P.
solanacearum indigenous to the soil at the ARC-FP, however, the plants
produced an overabundance of foliage and a light set of fruit smaller
than those produced by current Florida varieties.
Some of the lines bred by J. M. Walter and selected by J. M.
Walter, J. W. Strobel and P. Crill had slightly fewer plants killed
by the disease than the current Florida lines, however, further tests
will have to be run with these lines to determine if the survivors
were tolerant or escapes. D. S. Burgis (Horticulturist, AREC Braden-
ton, personal communication) states that J. M. Walter obtained a PI
line from N. N. Winstead in North Carolina in the late 1950's and
used it as the source of resistance in his lines. The line was appa-
rently the same used in developing Saturn and Venus. Walter selected
his lines for four generations in some cases exposing them to in-
fested soil. After his death, three generations were selected for
horticultural characteristics. Some resistance may have been lost at
the time horticultural characteristics were selected for.
Plants of the primitive PI 124608 survived well in the infested
soil. Crosses of this with Venus and Saturn or other lines are
The Hawaii lines were highly susceptible under the conditions of
the test. Gilbert (personal communication) indicated .that-the resis-
tance in these lines break down under high temperature. The Hawaii
resistance will probably not be useful in Florida because most of
the fall and spring tomatoes are subjected to high temperatures during
some part of their growing season.
Further screening is currently being conducted to find sources of
resistance to the P. solanacearum strain or strains present in south
Florida. Breeding"to incorporate different types of resistance into
Florida tomatoes is being conducted by R. B. Volin of IFAS AREC
Homestead and J. Augustine of IFAS AREC Bradenton.
1. Kelman, A. 1953. The bacterial wilt caused. y Pseudomonas
solanacearum. N. C. Agric. Exp. Stn. Tech. Bulf. 99.
2. Krausz, J. P. and H. D. Thurston. Breakdown of Resistance to
Pseudomonas solanacearum in tomato. Phytopathology 65:
3. Rao, M. V. B., H. S. Sohi, and Surinder K. Tikoo. 1975. Reaction
of wilt resistant tomato varieties ,c l -n:. th F-eudemonas
solanacearum in India. Plant. Dis. I:c;, c 9 .
4. ponoda, R. M. 1972. Control of tomato transplant damp-off.
Plant Dis. Reptr. 563~40-842.
Table 1. Incidence of bacterial wilt in 29 tomato accessions trans-
planted in Pseudomonas solanacearum infested soil on March 8,
1974 at the Agricultural Research Center, Fort Pierce.1/
703-1 54-2- 1-D1--Bk-I
1/ 4Mean daily maximum and minimum temperature; 83.6 and 61.4p respectively.
Rain recorded on nine of 69 days of experiment (Total 5.65 inch).
Table 2. Incidence of bacterial wilt it
Pseudomonas solanacearum infet
Agricultural Research Center,
1 50 tomato accessions transplanted in
ited soil on May 27, 1974 at the
Hawaii 7843 x Saturn
PI 281868 (No. 10)
PI 281866 (Linien 24a)
I/ Mean daily maximum and minimum temperature 87.7 and 67.3F, respectively.
Rain recorded on 15 of 36 days of experiment (Total 12.1 inch).
2/ Means followed by the same letter are
level (Duncan's multiple range test).
data transformed to arc-sine.
not significantly different at the 5%
Analysis of variance conducted on
Table 3. Incidence of bacterial wilt in 47 tomato accessions transplanted
in Pseudomonas solanacearum infested soil on 7-24-74 at the
Agricultural Research Center, Fort Pierce.1/
1/ Mean daily maximum and minimum temperature 88.5 and 72.1F, respectively.
Rain recorded on 10 of 31 days of experiment (Total 4.95 inch).
2/ Means followed by the same letter are not significantly different at the
5% level (Duncan's multiple range test). Analysis of variance conducted
on data transformed to arc-sine.