Prebreeding Tomato for Optimized Acylsugar-Mediated Insect Resistance

Martha Mutschler1, Darlene DeJong1, John Smeda2, Taylor Anderson1, Diane Ullman3

1 Plant Breeding and Genetics Section, SIPS, Cornell University2 Formerly Plant Breeding and Genetics Section, Cornell University; currently FSU

3 Dept. Of Entomology, UC-Davis

S. pennellii LA716 Cultivated tomato

Acylsugars and Insect Resistance

Two Series of Acylsugar Lines Bred for Differences in Acylsugar Level or Chemotype Form a Research Platform

Name Alteration in acylsugars produced by the line

Acylsugar Level and Chemistry Suppress Leaf Oviposition by WFT

Choice test: “Power washing” removes >77% of acylsugar

The probability of oviposition is ca. 0.50 if there if removing acylsugardroplets has no impact.

Entries with moderate/high levels of acylsugars have decreased WFT oviposition.

The acylsugar lines FA2/AS, FA7/AS and FA2/FA7/AS reduce probability of oviposition lower than CU071026

Ben-Mahmoud, Taylor Anderson et al. in prepUllman Lab, UC-Davis

Standard tomato, trace of acylsugar

Blocked acylsugar

production

Best WFT control

Acylsugar Level and Chemistry Work Together to Suppress

Inoculation of Leaves with TSWV by Western Flower Thrips

Entries with moderate-high acylsugar accumulation have decreased TSWV infection compared to tomato.

Lines FA2/AS, FA7/AS, and FA2/FA7/AS have significantly decreased TSWV infection vs tomato.

First instance of controlling virus by genetic control of the insect vector.

Cele

br i

ty

M82

CU

071026

FA

2/A

S

FA

7/A

S

FA

2/F

A7/A

S

FA

8/A

S

FA

2/F

A8/A

S

FA

5/A

S

0 .0 0

0 .2 5

0 .5 0

0 .7 5

1 .0 0

Pro

ba

bil

ity

of

TS

WV

In

oc

ula

tio

n

on

to U

nw

as

he

d L

ea

f D

isk

aa,b

a,b,c

c,d,ed,e

b,c,d

e

a,b,c

b,c,d

Standard tomato, trace of acylsugar

Blocked acylsugar

production

Reduced TSWV

Inoculation

Ben-Mahmoud, Taylor Anderson et al. in prepUllman Lab, UC-Davis

Acylsugar Level and Chemistry Impact SLW / TYLCV Inoculation in Field, Spr. 2014

Field trial done in cooperation with Hugh Smith and his staff

High, increasing numbers

of SLW across stages per

leaflet in the tomato

control and reduced

acylsugar lines

CU071026 and other

moderate acylsugar lines,

or higher acylsugar lines

maintain significantly

lower numbers of SLW

across stages per leaflet

Incidence of Tomato Yellow Leaf Curl Virus (TYLCV) Wimauma, Spring 2014

Data log10 (x+1) transformed before ANOVA; original means reported. Means not followed by same letter significantly different, Tukey’s studentized range test (α = 0.05)Field trial done in cooperation with Hugh Smith and his staff

Entry% plants positive

for TYLCV

FL-47 100%

FL X-1, heterozygous for Ty-3 75%

AS X AS hybrid #1 Heterozygous for Ty-3, low AS level 60%

CU071026 53%

AS X AS hybrid # 2 typical AS level 50%

AS X AS hybrid # 3 Heterozygous for Ty-3 & Increased AS QTL 30%

Homozygous for Ty-3 and increased AS QTL 0%

CU17NBL-1: New Acylsugar Benchmark Line with Good Fruit/Seed Set

Name or entry number

Differences in the S. pennellii introgression or sub-introgressions present in entry

2017 Field Results

Chr 3Chr 8

AS as % of CU071026

7 week Fruit

Counts

Ave. Fruit Wt (g)Top Mid-upper Center Mid-low Low

CU071026 YES YES YES YES YES NO 100.0 ab 7.3 j 83.5 a

AVRDC NO NO NO NO NO NO 15.9 d 60.8 a 75.8 a

OM3/+8/AS NO YES YES YES YES Full Length 100.6 ab 30.1 c-f 33.0 f

M3/Ty-3/AS YES NO YES NO YES NO 39.9 cd 8.9 ij 74.3 a

1 NO YES YES NO YES Full Length 92.8 ab 19.2 f-h 36.5 ef

2: CU17NBL-1 NO YES YES NO YES Shortened 101.8 ab 41.7 b-d 50.7 bc

3 NO YES YES NO YES Full Length 116.7 a 22.2 f-h 37.1 ef

4: CU17NBL-2 NO YES YES NO YES Shortened 114.3 ab 50.6 ab 45.4 cd

Other Horticultural Traits That Must Be Improved in Acylsugar Lines: Mapping

Negative traits: small fruit, short bushy plant, off flavor

First step:

Other Horticultural Traits That Must Be Improved in Acylsugar Lines: Mapping

Impact of Chr 8 QTL in CU17NBL-1 on acylsugar level revealed:

Horticultural Traits That Must be Improved in Acylsugar Lines: SMALL FRUIT

• Chr. 10U

• Chr. 2.

• Chr. 3.

Horticultural traits that must be improved in acylsugar lines: OFF FLAVOR.

Horticultural Traits That Must be Improved in Acylsugar Lines: OFF FLAVOR.

Localization of QTL For Off Flavor Trait.

EntriesA / Seed Source

Is flavor

normal or

off?

Markers within the Chr3 introgression

sucr

3g0

31

00

SSR

11

1

3g1

02

20

4g3

96

30

5g6

01

60

1g0

53

50

3g4

83

30

5g5

28

20

U1

46

89

9

5g1

30

50

5g4

99

70

5g2

30

60

Location of marker in Mb

33

.3

59

.3

59

.4

60

.5

61

.2

61

.8

61

.9

62

.4

62

.9

63

.1

63

.7

63

.8

64

.4

CK-12 (F5) tomato Normal 1 1 1 1 1 1 1 1 1 1 1 1 1

CU071026 Off 3 3 3 3 3 3 3 3 3 3 3 3 3

171007-22 Off 1 1 1 3 3 3 3 3 3 3 3 3 3

171008-06 Off 1 1 1 3 3 3 3 3 3 3 3 3 3

171014-45 Off 1 1 1 1 1 1 1 1 1 1 3 3 3

171010-44 Normal 1 1 1 1 1 1 1 1 1 1 1 1 1

CU17NBL-1, -2, and -3 Off 3 3 3 3 1 1 1 1 1 3 3 3 3

Range of off flavor QTL Off flavor 1.3 MbA All AS entries homozygous for chr 2, 7, 10Upper introgressions. CU17NBL-1, -2, and -3 also has Chr 8 introgression

• Plants with recombinations from 64.1 to 64.4MB have been isolated for elimination of trait• 171010-44 is example of line without lower Chr 3, but normal AS level due to presence of Chr 8. region

Summary:

The process of eliminating QTL associated with negative horticultural traits is well underway: proceeding faster than anticipated.

Acknowledgements

• Mutschler Lab (Plant Breeding and Genetics, Cornell

Breeding insect and disease resistant tomatoes

− Darlene De Jong

− John Smeda

− Taylor Anderson

− Michael Glos

− Julie Bojanowski

• Ullman Lab (Entomology, UC-Davis)

western flower thrips and TSWV

− Diane Ullman

− Sulley Ben Mahmoud

• Kennedy Lab (Entomology, NCSU)

western flower thrips and TSWV

− George Kennedy

− Thomas Chappell

Horticultural Traits That Must Be Improved in Acylsugar Lines: SHORT BUSHY PLANT