Resistance to Soybean Rust in Dry Beans. - Plant Management ...

Resistance to Soybean
Rust in common bean
M. A. Pastor-Corrales
USDA-ARS
Soybean Genomics and Improvement
Laboratory
Beltsville Agricultural Research Center
Beltsville, Maryland

Some Salient Soybean
Attributes Rust
of
Soybean rust
Moves swiftly
A very aggressive plant pathogen
Causes very severe yield losses and
damage to soybean
All commercial soybean cultivars
are Susceptible
Broad host range
Potentially an important disease of
other leguminous crops

Soybean Rust Reports
Japan 1902 Brazil 2002
Australia 1934 Argentina 2002
Hawaii 1994 Bolivia 2003
Uganda 1996 Uruguay 2004
Zimbabwe 1998 USA 2004
Nigeria 1999 Mexico 2005
South Africa 2001 Ghana 2006
Paraguay 2001 D.R. Congo 2007

Some Salient Soybean
Attributes Rust
of
Soybean rust
Moves swiftly
A very aggressive plant pathogen
Causes very severe yield losses and
damage to soybean
All commercial soybean cultivars
are Susceptible
Broad host range
Potentially an important disease of
other leguminous crops

Premature defoliation of soybeans by
Soybean Rust (Brazil)

Some Salient Soybean
Attributes Rust
of
Soybean rust
Moves swiftly
A very aggressive plant pathogen
Causes very severe yield losses and
damage to soybean
All commercial soybean cultivars
are Susceptible
Broad host range
Potentially an important disease of
other leguminous crops

Hosts of Soybean Rust
LEGUMES (Papilionoideae)
• Cultivated Crops:
Glycine max (soybeans)
Phaseolus vulgaris (Dry and Snap beans; e.i., i.e.., kidney beans)
Phaseolus lunatus (lima and butter beans)
Vigna unguiculata (cowpeas)
Cajanus cajan (pigeon peas)
Pachyrhizus erosus (yam bean, jicama)
• Ornamental plants:
Hyacinth bean, lupine,
royal poinciana
• Wild hosts:
Kudzu, sweet clover

Some Soybean Salient Attributes Rust of
Soybean rust
Originated in Asia
Caused by Phakopsora pachyrhizi
A very aggressive plant pathogen
Moves swiftly
Causes very severe yield losses and
damage to soybean
Broad host range
Potentially an important disease
of other leguminous crops

SBR has been reported
infecting common beans under
field conditions
• South Africa
– Plant Disease, February 2005
• United States
– Plant Disease, July 2006
• Argentina
– Plant Disease, January 2007
• Brazil
– Various reports, 2006, 2007

SBR - Symptoms caused by
Phakopsora pachyrhizi on
Phaseolus vulgaris
Bean rust symptoms caused
by Uromyces appendiculatus
on Phaseolus vulgaris

The common bean
(Phaseolus vulgaris)
The most important legume for direct
human consumption in the world
Seed of dry beans
Consumed as
Pods of snap beans

Navy
Dark Red Kidney

Studying the differential
Response of Common Bean to
SBR Isolates
• Little information on the interaction
of individual isolates of P.
pachyrhizi with common bean
germplasm
• 16 common bean cultivars
challenged with six isolates of the
SBR pathogen
• Isolates were from Asia, Africa,
Latin America

Studying the differential
Response of Common Bean to
SBR Isolates
• Little information on the interaction
of individual isolates of P.
pachyrhizi with common bean
germplasm
• 16 common bean cultivars
challenged with six isolates of the
SBR pathogen
• Isolates were from Asia, Africa,
Latin America

Studying the differential
Response of Common Bean to
SBR Isolates
• Little information on the interaction
of individual isolates of P.
pachyrhizi with common bean
germplasm
• 16 common bean cultivars
challenged with six isolates of the
SBR pathogen
• Isolates were from Asia, Africa, Latin
America

Differential Response of Common
Bean Cultivars to SBR Isolates
• Emphasis on beans with genes for
resistance to the common bean
rust Uromyces appendiculatus
• Work was conducted under GH
conditions in the USDA-ARS
Foreign Disease-Weed Science
Research Unit BSL-3 Containment
greenhouse at Ft. Detrick, MD

Differential Response of Common
Bean Cultivars to SBR Isolates
• Emphasis on beans with genes for
resistance to the common bean
rust Uromyces appendiculatus
• Work was conducted under GH
conditions in the USDA-ARS
Foreign Disease-Weed Science
Research Unit BSL-3 Containment
greenhouse at Ft. Detrick, MD

Bean cultivars inoculated with six
Phakopsora pachyrhizi isolates
Bean Cultivar Bean Type Resistance Gene
Pinto 114 Dry bean None
Aurora Dry bean Ur-3
Early Gallatin Snap bean Ur-4
Mexico 309 Dry bean Ur-5
Golden White Wax Snap bean Ur-6
PI 181996 Dry bean Ur-11
CNC Dry bean Ur-C?, Ur-N?
PI 260418 Dry bean Ur-P? ,Ur- I?

ARS bean germplasm lines
inoculated with six Phakopsora
pachyrhizi isolates
Bean Cultivar Bean Type Resistance Gene
BelMiDak-RMR-10 Dry bean-ARS/Navy Ur-4, -11
BelNeb-RR-1 Dry Bean – ARS/GN Ur-5, -6, -7
BelMiNeb-RMR-5 Dry bean-ARS/GN Ur-4, -6, -11
BelMiNeb-RMR-7 Dry bean-ARS/GN Ur-3, -4, -11
BelDak-RR-2
Dry bean-ARS/Pinto Ur-3, -6, CNN
BelDakMi-RMR-14 Dry bean-ARS/Pinto Ur-3, -4, -11
BelMiNeb-RMR-8 Dry bean-ARS/GN Ur-3, -4, -6, -11
BelDakMi-RMR-18 Dry bean-ARS/Pinto Ur-3, -4, -6, -11

Soybean cultivars - Checks
Soybean
Accession
Resistance
genes
PI 200492 (Komata) Rpp1
PI 230970
Rpp2
Ina
None; Mod. Susc.
PI 459025B (Bing-Nan) Rpp4

Six Isolates of Phakopsora
Pachyrhizi used in this
study
• TW72-1 Taiwan
• TW80-2 Taiwan
• TH01-1 Thailand
• ZM01-1 Zimbabwe
• BZ01-1 Brazil
• PG01-2 Paraguay

Soybean Rust-Soybean Interactions
Red Brown
HR
Necrotic spot
Tan
Susceptible

Soybean Rust Severity Scale
1-5 Scale
• 1 = No visible lesions
• 2 = Few Scattered lesions present
• 3 = Moderate number of lesions on
at least part of the leaf
• 4 = Abundant number of lesions on
at least part of the leaf
• 5 = Prolific lesion development over
most of the leaf

Soybean Rust Sporulation Scale
1-5 Scale
• 1 = No sporulation
• 2 = Present on but less than 25% of
a fully sporulating lesion
• 3 = Sporulation equal to 26 t0 50% of
a fully sporulating lesion
• 4 = Sporulation equal to 51 t0 75% of
a fully sporulating lesion
• 5 = Sporulation equal to a fully
sporulating lesion

Differential Response of common
bean to Phakopsora pachyrhizi
• As a group, common cultivars
appeared to have resistance to
SBR
• None were immune
• When compared with Soybean
cv. Ina, were similar in severity
but had less sporulation

Differential Response of common
bean to Phakopsora pachyrhizi
• As a group, common cultivars
appeared to have resistance to
SBR
• None were immune
• When compared with Soybean
cv. Ina, common bean cultivars
were similar in severity but had
less sporulation

Mean Soybean Rust severity and Sporulation of 16 common
Bean Cultivars inoculated with six isolates of SBR pathogen
_
X=2.9
_
X=3.1
_
X=2.8
_
X=4.2

5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
Common bean cultivars Aurora,
CNC, and PI 181996 had lower
SBR severities than soybean Ina
Soybean Rust Severity
2.7 3.3
2.9
2.9 3.0 3.0 2.9 3.2 2.8 2.4 2.9 3.2 3.4 2.7 2.8 2.8
3.1 3.1
3.0
3.5
Aurora
BDM-RMR-14
BDM-RMR-18
BelDak-RR-2
BMD-RMR-10
BMN-RMR-5
BMN-RMR-7
BMN-RMR-8
BelNeb-RR-1
CNC
Early Gallatin
Golden W.W.
Mexico 309
PI 181996
PI 260418
Pinto 114
Ina
PI 200492
PI 230970
PI 459025B
Common beans and Soybeans
Mean severity

Common bean cultivars Aurora, CNC, PI
181996, and Pinto 114 had significantly
lower SBR sporulation than soybean Ina
Soybean rust sporulation
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
2.3 4.2 3.6 2.4 3.4 3.7 2.8 3.7 2.7 3.3 4.8 4.8
1. 6
3.2 2.1 2.6 2.0 2.0
3.0 3.5
Aurora
BDM-RMR-14
BDM-RMR-18
BelDak-RR-2
BMD-RMR-10
BMN-RMR-5
BMN-RMR-7
BMN-RMR-8
BelNeb-RR-1
CNC
Early Gallatin
Golden W.W.
Mexico 309
PI 181996
PI 260418
Pinto 114
Ina
PI 200492
PI 230970
PI 459025B
Common beans and soybeans
Mean sporualation

Differential Response of Common
Bean Cultivars to SBR Isolates
• Cultivar-Isolate interaction was
significant
• All common bean cultivars did not
respond similarly to each SBR isolate
for both, severity and sporualtion

Bean Cultivar - SBR Isolate
Interaction
Severity

Bean Cultivar - SBR Isolate Interaction
Severity

Bean Cultivar - SBR
Isolate Interaction
Sporulation

Bean Cultivar - SBR Isolate Interaction
Sporulation

Differential Response of
Common Bean to SBR Isolates
Summary
• Bean cultivars CNC, PI
181996, Aurora and Pinto
114 were the most resistant
to all six isolates of SBR
pathogen
• These cultivars had lower
severity, less sporulation,
and consistent RB (resistant)
lesions

Differential Response of
Common Bean to SBR Isolates
Summary
• A differential response was observed
among bean cultivars with a cultivarisolate
interaction for severity and
sporulation
• Resistance to SBR in common bean
was independent of the resistance to
Uromyces appendiculatus
• Pinto 114, universally susceptible to
U. appendiculatus – Resistant to SBR
• BDM-RMR-18 with four genes for
resistance to U. p. –one of the most
susceptible to SBR

Inheritance of Resistance to
Soybean Rust in common bean
Severity reaction to
Phakopsora pachyrhizi
isolates
BZ01-1 PG01-1 TH01-1 TW72-1 TW80-2 ZM01-1
CNC 2.1 2.3 2.5 2.6 2.4 2.6
Mex.
309 3.7 3.7 3.0 3.4 3.4 3.4

4.0
3.5
3.0
2.5
2.0
1.5
CNC
Mexico 309
1.0
0.5
0.0
BZ01-1 PG01-1 TH01-1 TW72-1 TW80-2 ZM01-1
Reaction to Phakopsora pachyrhizi isolates
Soybean Rust Severity Rating

Inheritance of Resistance to
Soybean Rust in common bean
Soybean Rust Sporulation
Sporulation to Phakopsora
pachyrhizi isolates
BZ01-
1
PG01-
2
TH01-
1
TW72-
1
TW80-
1
ZM01-
1
CNC 1.5 1.5 2.1 1.3 1.3 1.8
Mex. 309 3.4 2.5 2.5 1.8 3.1 2.6

3.5
3.0
2.5
2.0
1.5
CNC
Mexico 309
1.0
0.5
0.0
BZ01-1 PG01-2 TH01-1 TW72-1 TW80-1 ZM01-1
Reaction to Phakopsora pachyrhizi isolates

3.5
3.0
2.5
2.0
1.5
CNC
Mexico 309
1.0
0.5
0.0
BZ01-1 PG01-2 TH01-1 TW72-1 TW80-1 ZM01-1
Reaction to Phakopsora pachyrhizi isolates

Inheritance of SBR resistance
in common bean CNC
• Cross: Mexico 309 (S) x CNC (R)
• Two F 2 populations
– P1: 117 F 2 plants
– P2: 124 F 2 plants
• All F 2 plants, R and S parents and
soybean check inoculated with
Brazilian isolate (BZ-1-1)

Total 117 124 241
F 2
Mexico 309 x CNC Phenotype based on Severity
First batch Second batch Both Batches
Grade # # #
2 6 10 16
3 63 61 124
4 37 45 82
5 11 8 19

Segregation for Resistance in CNC to
Phakopsora pachyrhizi (BZ01-1)
Observed
R S
Expected
Ratio χ P
F 2
140 101 9R:7S 0.01 0.9
F 2
140 101 3R:1S 13.6
F 2
140 101 13R:3S 45.3

Resistance in CNC to SBR
• Results suggest that resistance in CNC is
controlled by the interaction of two genes
• Complete dominance at both gene pairs
• Either recessive homozygote is epistatic
to the effects of the other gene
• A_B_ = 9 Resistant
• A_bb = 3 Susceptible
• aaB_ = 3 Susceptible
• Aabb = 1 Susceptible

Resistance in CNC to SBR
• Results suggest that resistance in CNC is
controlled by the interaction of two genes
• Complete dominance at both gene pairs
• Either recessive homozygote is epistatic
to the effects of the other gene
• A_B_ = 9 Resistant
• A_bb = 3 Susceptible
• aaB_ = 3 Susceptible
• Aabb = 1 Susceptible

Summary
• Common beans appear to be much less
susceptible to ASR than Soybeans
• Resistance in common bean offers a number
of opportunities for further studies with
potential of leading to new genetic options
for the control of the ASR pathogen
• Further studies are needed to understand
and characterize the resistance genes in
common bean to the ASR pathogen
• Research should benefit dry and snap beans
and possibly soybeans

Present and Future SRB Work
• Search for molecular markers linked to
SBR resistance genes in CNC
• Evaluate common bean core collection
with selected isolates of SBR, include
snap beans and commercial dry beans
• Search for additional SBR resistance
genes & possible vulnerabilities
• If SBR resistance genes in common
bean could be cloned - they could be
used to genetically engineer soybeans
with resistance to ASR

Glen
Hartman
Monte
Miles
Reid
Frederick
Morris
Bonde