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 Introduction
 Screening techniques
 Breeding and genetics
 Reference
 Tables






Group Title: Mimeo report - Agricultural Research & Education Center - BR71-4
Title: Breeding tomatoes for resistance to Race 2 Fusarium wilt
CITATION PAGE IMAGE ZOOMABLE PAGE TEXT
Full Citation
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Permanent Link: http://ufdc.ufl.edu/UF00067667/00001
 Material Information
Title: Breeding tomatoes for resistance to Race 2 Fusarium wilt
Series Title: Mimeo report AREC
Physical Description: 3, 3 leaves : ; 28 cm.
Language: English
Creator: Crill, Pat, 1939-
Jones, J. P ( John Paul ), 1932-
Woltz, S. S
Agricultural Research & Education Center (Bradenton, Fla.)
Publisher: Agricultural Research & Education Center
Place of Publication: Bradenton Fla
Publication Date: 1971
 Subjects
Subject: Tomatoes -- Breeding -- Florida   ( lcsh )
Tomatoes -- Diseases and pests -- Control -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Includes bibliographical references (leaf 3).
Statement of Responsibility: Pat Crill, J.P. Jones, and S.S. Woltz.
General Note: Caption title.
General Note: "January, 1971."
Funding: Bradenton AREC mimeo report
 Record Information
Bibliographic ID: UF00067667
Volume ID: VID00001
Source Institution: Marston Science Library, George A. Smathers Libraries, University of Florida
Holding Location: Florida Agricultural Experiment Station, Florida Cooperative Extension Service, Florida Department of Agriculture and Consumer Services, and the Engineering and Industrial Experiment Station; Institute for Food and Agricultural Services (IFAS), University of Florida
Rights Management: All rights reserved, Board of Trustees of the University of Florida
Resource Identifier: oclc - 71816308

Table of Contents
    Copyright
        Copyright
    Introduction
        Page 1
    Screening techniques
        Page 1
    Breeding and genetics
        Page 2
    Reference
        Page 3
    Tables
        Page 4
        Page 5
        Page 6
Full Text





HISTORIC NOTE


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
(EDIS)

site maintained by the Florida
Cooperative Extension Service.






Copyright 2005, Board of Trustees, University
of Florida






ri; AGRICULTURAL RESEARCH & EDUCATION C NTEU L R
F 6 / Bradenton, Florida AR 97

SMimeo Report AREC-BR71-4 January, 1971

BREEDING TOMATOES FOR RESISTANCE TO RACE 2 F tfliSWID 11 0

Pat Crill, J. P. Jones, and S. S. Woltz

INTRODUCTION

Two sources of resistance to Fusarium wilt of tomato have been employed to con-
trol this most important tomato disease; a) a polygenic tolerance mechanism, and
b) a monogenic resistance mechanism (Walter, 1967). Historically, tomato breeders
and pathologists have preferred to control tomato Fusarium wilt by using monogenic
resistance. Van der Plank (1968), however, proposed that for best results poly-
genic resistance should be utilized exclusively to control Fusarium wilt of tomato.
Despite Van der Plank's suggestions, tomato breeders in Florida continue to prefer
controlling Fusarium wilt with monogenic resistance.

Prior to 1941 the only source of resistance to Fusarium wilt was the polygenic
tolerance type. In 1941 the Pan America variety was released (Porte & Walker,
1941) which possessed the Il monogene for resistance to race 1 of Iuu~ i' wilt.
Tomato breeders immediately utilized this gene and most of the later releases
contained the I1 gene. In 1945 Alexander and Tucker (1945) reported the occur-
rence of race 2 Fusarium wilt in Ohio. Gerdemann and Finley (1951) reported an
isolate of Fusarium which would overcome the Il monogene and in 1960 Stall (1961a,
1961b) reported the occurrence of race 2 in Florida. Since 1961 race 2 has been
found in many other states including Arkansas, North Carolina, Nc-: Jersey, and
Georgia, and it has been reported in the countries of Mexico, Brazil, Windward
Islands, France, Belgium, Israel, and North Africa. At the present time race 2
Fusarium wilt is the most serious tomato disease incited by a soil-bcrne pathogen
in Florida.

SCREENING TECHNIQUES

A dependable technique for the determination of resistance is indi'ppensablc for
breeding and genetic studies. The root dip method yields the quickest, most
dependable results. With this method the seedlings are uprooted (tearing away
part of the roots), immersed a few seconds in a dense suspension of F7snri',-
cells, transplanted into pasteurized soil, and incubated at 82 F.

Although Fusarium wilt development is affected by day length, light intensity,
temperature, nutrition, soil pH, and soil moisture, these factors have been ig-
nored by most workers using the root dip method because it was thought that wilt
was not seriously affected within the ranges regarded as optimum for the tomato
crop. However, for consistent results which avoid escapes that confound genetic
ratios, some of the environmental factors should be controlled as far as feasible.

Race 2 will not grow well, will not sporulate, and is nearly non-pathogenic when
grown in liquid cultures devoid of micronutrients (Table 1). Excellent control
of race 2 and large yield increases are obtained in the greenhouse and field by
liming to a pH of 7.0-8.0 (Tables 2 & 3). In fact, yields are increased as much
by liming to pH 7.0 as by fumigating pH 6.0 soil with Vorlex or chloropirin +
D-D.

The control of Fusarium wilt is due to an induced deficiency of micronutrients,
not to an increased calcium content in the soil or in the tomato plants (Tables
2 & 3). The lime effect can be reversed by amending the high pH soil with






ri; AGRICULTURAL RESEARCH & EDUCATION C NTEU L R
F 6 / Bradenton, Florida AR 97

SMimeo Report AREC-BR71-4 January, 1971

BREEDING TOMATOES FOR RESISTANCE TO RACE 2 F tfliSWID 11 0

Pat Crill, J. P. Jones, and S. S. Woltz

INTRODUCTION

Two sources of resistance to Fusarium wilt of tomato have been employed to con-
trol this most important tomato disease; a) a polygenic tolerance mechanism, and
b) a monogenic resistance mechanism (Walter, 1967). Historically, tomato breeders
and pathologists have preferred to control tomato Fusarium wilt by using monogenic
resistance. Van der Plank (1968), however, proposed that for best results poly-
genic resistance should be utilized exclusively to control Fusarium wilt of tomato.
Despite Van der Plank's suggestions, tomato breeders in Florida continue to prefer
controlling Fusarium wilt with monogenic resistance.

Prior to 1941 the only source of resistance to Fusarium wilt was the polygenic
tolerance type. In 1941 the Pan America variety was released (Porte & Walker,
1941) which possessed the Il monogene for resistance to race 1 of Iuu~ i' wilt.
Tomato breeders immediately utilized this gene and most of the later releases
contained the I1 gene. In 1945 Alexander and Tucker (1945) reported the occur-
rence of race 2 Fusarium wilt in Ohio. Gerdemann and Finley (1951) reported an
isolate of Fusarium which would overcome the Il monogene and in 1960 Stall (1961a,
1961b) reported the occurrence of race 2 in Florida. Since 1961 race 2 has been
found in many other states including Arkansas, North Carolina, Nc-: Jersey, and
Georgia, and it has been reported in the countries of Mexico, Brazil, Windward
Islands, France, Belgium, Israel, and North Africa. At the present time race 2
Fusarium wilt is the most serious tomato disease incited by a soil-bcrne pathogen
in Florida.

SCREENING TECHNIQUES

A dependable technique for the determination of resistance is indi'ppensablc for
breeding and genetic studies. The root dip method yields the quickest, most
dependable results. With this method the seedlings are uprooted (tearing away
part of the roots), immersed a few seconds in a dense suspension of F7snri',-
cells, transplanted into pasteurized soil, and incubated at 82 F.

Although Fusarium wilt development is affected by day length, light intensity,
temperature, nutrition, soil pH, and soil moisture, these factors have been ig-
nored by most workers using the root dip method because it was thought that wilt
was not seriously affected within the ranges regarded as optimum for the tomato
crop. However, for consistent results which avoid escapes that confound genetic
ratios, some of the environmental factors should be controlled as far as feasible.

Race 2 will not grow well, will not sporulate, and is nearly non-pathogenic when
grown in liquid cultures devoid of micronutrients (Table 1). Excellent control
of race 2 and large yield increases are obtained in the greenhouse and field by
liming to a pH of 7.0-8.0 (Tables 2 & 3). In fact, yields are increased as much
by liming to pH 7.0 as by fumigating pH 6.0 soil with Vorlex or chloropirin +
D-D.

The control of Fusarium wilt is due to an induced deficiency of micronutrients,
not to an increased calcium content in the soil or in the tomato plants (Tables
2 & 3). The lime effect can be reversed by amending the high pH soil with








lignosulfonate-micronutrient complexes which are available at high soil pH values
(Table 4).

The growth of Fusarium, following introduction into limed, high pH pasteurized
soil, is limited. Growth of the fungus is enhanced in high or low pH soil by
the addition of micronutrients. These micronutrients are so essential for
Fusarium growth and virulence that the root dip method will yield poor or incon-
sistent results if inoculated seedlings are transplanted to soils deficient in
micronutrients (Table 2).

The test seedlings should be grown prior to inoculati6n'in nitrogen-poor soils
since plants low in nitrogen are more susceptible to wilt than plants high in
nitrogen (Table 5). Calcium and magnesium nutrition does not materially affect
wilt development.

Inoculum concentration should be adjusted properly for a successful test. If the
concentration is too low, wilt may not develop or there will be many escapes (Table
6). An easy method to obtain the proper concentration is to grow the Fusarium
on potato-dextrose agar plates at 82 F until the agar surface is fully covered,
then grind the agar and fungal mat in a Waring Blender with just enough water to
permit blending.

BREEDING AND GENETICS

The philosophy underlying the Florida tomato breeding program is to use monogenic
resistance for disease control wherever possible. Alexander and Hoover (1953),
and Alexander (1959) located resistance to race 2 in several sources. Subsequently
Stall and Walter (1965) verified this and incorporated race 2 resistance into the
breeding program. This work eventually culminated in the release of the variety
WALTER by Strobel, et al. (1969).

Stall and Walter (1965) concluded that resistance to races 1 and 2 was inherited
as a single dominant gene. They were not, however, able to determine whether a
single gene governed resistance to both races or whether separate genes governed
resistance to each race. Cirruli and Alexander (1966) tentatively suggested that
resistance to each race was probably governed by separate genes, and the gene for
resistance to race 2 be designated as 1-2.

At the present time the only tomato variety available which possesses the 1-2 gene
for resistance to race 2 of Fusarium wilt is WALTER. The value of the 1-2 gene is
indicated by the rapid acceptance of the variety WALTER by Florida tomato growers.
In those areas in Florida where the variety is adapted (short-stake and acid soils)
it has virtually replaced all others. The race 2 Fusarium wilt pathogen is so wide-
spread in Florida that no variety releases are anticipated which do not possess the
1-2 gene. All advanced breeding lines must possess homozygous resistance to race
2 or they are eliminated from consideration for the Southern Tomato Exchange Pro-
gram (STEP) trials or variety release.

Extensive experiments are underway to determine the inheritance of resistance to
race 2 Fusarium wilt in tomato. All experiments are based on Alexander's hypo-
thesis that separate genes control resistance to races 1 and 2. The three geno-
types, ilili2i2, I111i2i2, and 11111212 have been located and confirmed. The
genotype ilill212 has not been located but is being synthesized from the cross
i1ili2i2 x 11111212. Because either race 1 or race 2 will kill the F2 plants
all screening is done in the F3. Part of each F3 family is screened for resistance
to one race and then the other. These data are then used to extrapolate the








individual F2 plant reaction to both races. The genotype ilil1212 has not been
located at this time, but should be confirmed shortly.


LITERATURE CITED

1. Alexander, L. J. 1959. Progress report of national screening committee for
disease resistance in the tomato for 1954-1957. Plant Dis. Reptr. 43:55-65.

2. Alexander, L. J., and M. M. Hoover. 1953. Progress report of national screen-
ing committee for disease resistance in the tomato for 1952. Plant Dis.
Reptr. 37:317-324.

3. Alexander, L. J., and C. M. Tucker. 1945. Physiological specialization in
the tomato wilt fungus Fusarium oxysporum f. lycopersici. Jour. Agr. Res.
70:305-313.

4. Cirulli, M., and L. J. Alexander. 1966. A comparison of pathogenic isolates
of Fusarium oxysporum f. lycopersici and different sources of resistance in
tomato. Phytopathology 56:1301-1304.

5. Gerdemann, J. W., and A. M. Finley. 1951. The pathogenicity of races 1 and
2 of Fusarium oxysporum f. lycopersici. Phytopathology 41:238-244.

6. Porte, W. S., and H. B. Walker. 1941. The Pan-America tomato, a new red
variety highly resistant to Fusarium wilt. U.S.D.A. Agric. Circ. 611.

7. Stall, R. E. 1961a. Development of Fusarium wilt on resistant varieties of
tomato caused by a strain different from race 1 isolates of Fusarium oxysporum
f. lycopersici. Plant Dis. Reptr. 45:12-15.

8. Stall, R. E. 1961b. Development in Florida of a different pathogenic race of
the Fusarium wilt of tomato organism. Fla. State Hort. Soc. Proc. 74:175-177.

9. Stall, R. E., and J. M. Walter. 1965. Selection and inheritance of resistance
in tomato to isolates of races 1 and 2 of the Fusarium wilt organism.
Phytopathology 55:1213-1215.

10. Strobel, J. W., N. C. Hayslip, D. S. Burgis, and P. H. Everett. 1969. Walter -
a determinate tomato resistant to races 1 and 2 of the Fusarium wilt pathogen.
Univ. of Fla., IFAS Circ. S-202.

11. Van der Plank, J. E. 1968. Disease resistance in plants. Academic Press,
Inc. New York, N.Y.

12. Walter, J. M. 1967. Hereditary resistance to disease in tomato. Ann.
Review of Phytopathology 5:131-162.













Table 1. Effect of micronutrients on growth, sporulation, and virulence
of Fusarium oxysporum f. sp. lycopersici race 2 in liquid cultures.




Micronutrients Fresh wt of 106 spores/ml Percent plants
mycelial mats(g) solution diseased

None 0.38 0.00 90
1 x complete 6.95 5.31 93
4 x complete 8.20 9.38 93
Complete-0 Fe 6.97 8.46 90
Complete-0 Mn 6.61 2.64 90
Complete-0 Zn 2.29 0.51 38


1 x complete =


B 0.1 ppm, Cu 0.1 ppm, Fe 1 ppm, Mn
Mo 0.01 ppm


0.5 ppm, and Zn 0.5 ppm,


Table 2. Effect of hydrated lime on development
of Fusarium wilt of tomato in the green-
house


Inoculated Healthy
Soil treatment transplants transplants
% incidence % incidence

Unlimed 86a 98a
Limed 57 37
------------------------------------
Unlimed 88b
CaS04 79
Ca(OH)2 43


aAverage of 4 tests
bAverage of 2 tests










Table 3. Effect of pH on Fusarium wilt in the field.


Mark.
Soil Percent yields % tissue
Treatment pH disease (bu/A) calcium

Sulfur 6.0 80 600 0.91-1.25
Ca(OH)2 7.5 50 734 0.99-1.01
Ca(OH)2 8.0 50 723 0.97-1.27


Table 4. Effect of soil amendments of lignosulfonate-metal complexes, hydrated
lime + ground limestone, and gypsum on the incidence and severity of
Fusarium wilt.



Rate of
each ligfto- Lignosulfonate-metal complexes used
sulfonate Fe + Mn + Znb Fe + Mnb Mn + Znb Fe + Znb Fe + Mn + Znc
Mg/kg soil % index % index % index % index % index

400 37.5 1.06 37.5 1.12 93.7 3.25 87.5 3.12 87.5 3.37
200 37.5 1.37 25.0 0.81 87.5 2.68 81.2 2.50 93.7 3.43
100 37.5 1.06 37.5 1.18 62.5 1.50 67.7 1.50 100.0 3.75
50 37.5 1.25 50.0 1.37 25.0 0.68 50.0 1.37 100.0 3.93
0 56.2 1.62 81.2 2.81


LSD 05 incidence and index = 40 and 0.98 respectively


a5% metal
bAmended with Ca(OH)2 + CaCO3 each at rate of 1,000 mg/kg soil.
CAmended with CaS04 + 2H20 at the rate of 2,000 mg/kg soil.
dBased on a 0-5 scale where 0 = no disease and 5 = dead plants.
















Table 5. Effect of nutritional preconditioning
on incidence of Fusarium wilt.



Plant PPM % dead
nutrition N Ca plants

Control 150 40 17.5
Low N 50 40 65.0
High N 450 40 10.8
High Ca 150 360 25.8
O Ca, O Mg 150 0 15.0


P = 40 ppm, K = 200 ppm





Table 6. Effect of inoculum concentration
on disease development.



Number % disease
spores/ml incidence

15,000,000 100
4,500,000 92
350,000 67
60,000 17
40,000 21
25,000 0
15,000 0
Mycelium (1 mg/ml) 98
Mycelium (0.1 mg/ml) 12




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