Hopper Adaptation

1
Hopper Adaptation an inconvenient truth
Finbarr G. Horgan CESD-IRRI
2
Brown Plant Hopper (BPH) White-backed Plant
Hopper (WBPH)
IRRI
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IRRI
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Central Thailand-Nov 2009
IRRI
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Santa Cruz, Philippines-Mar 2009
IRRI
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Pila, Philippines-Mar 2009
IRRI
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Pila, Philippines-Mar 2009
IRRI
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IRRI
9
IRRI
10

• Varietal deployment 0
• Gene deployment 0
• Effectiveness of pyramiding 0
• Deployment networks 0
• Farmer acceptance 0

IRRI
11
Bph1 IR26, IR28, IR29, IR30, IR64 bph2 IR32,
IR36, IR38, IR40, IR42 Bph3 IR58, IR62, IR72,
IR74 Bph10 IR65482-4-136-2-2 bph11
IR75742-23-19-12-3 Bph13 IR54745-2-21-12-17-6
Bph18 IR65482-7-216-1-2 and Chinese hybrids Bph
14, Bph15 B5 and Chinese Hybrids.
IRRI
12
CSISA, ADB and SKEP Development of NILs and
PYLs with major resistance genes Darshan Brar,
Daisuke Fujita, Parminder Virk Hideshi Yasui
IRRI
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Alam Cohen 1998
Bph3
None
IR22
IR72
survival
Bph1
Bph1
IR64
IR26
Generation
Banaue
C. Luzon
IRRI
IRRI
14
IR22
IR72
Female wgt.
Feeding rate
Dev. T.
Survival
Female wgt.
Feeding rate
IRRI
15
Ketipearachchi et al 1998
survival
Thai.Col.11
Pokkali
IRRI
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Ketipearachchi et al 1998
survival
Thai.Col.11
Pokkali
12th generation
No. eggs/plant
Variety
IRRI
17
Ketipearachchi et al 1998
survival
Thai.Col.11
Pokkali
12th generation
Bph8
No. eggs/plant
Bph9
Variety
IRRI
18
Ketipearachchi et al 1998
survival
Thai.Col.11
Pokkali
12th generation
Bph9
No. eggs/plant
Bph8
Variety
IRRI
19
Grh2
Grh ?
nymphs surviving
Grh2 Grh4
Generation
Hirae et al 2007
IRRI
20
Grh2
Grh ?
nymphs surviving
nymphs to instar 2
Grh2 Grh4
Generation
Variety
Hirae et al 2007
IRRI
21
Grh2
Grh ?
nymphs surviving
nymphs to instar 2
Grh2 Grh4
Generation
Grh3
Variety
Hirae et al 2007
IRRI
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Relict colonies in Kyushu, Japan 1966, 1989,
1999, 2005
Myint et al 2009
IRRI
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Wbph2
Differentials
Wbph1, Bph1, bph2, bph4, bph8
bph2, bph4, bph8
Bph1
Year
Myint et al 2009
IRRI
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Bph21 bph20 in ADR52
Myint et al (unpublished)
Wbph2
Differentials
Wbph1, Bph1, bph2, bph4, bph8
bph2, bph4, bph8
Bph1
Year
Myint et al 2009
IRRI
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Occurrence of a New Russian Wheat Aphid Biotype
in Colorado
Haley et al 2004
IRRI
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Multiple gene breakdown?
IRRI
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• Resistance genes have been breaking down,
  already 6 genes are known not to function in SE
  Asia (but only a few have ever been tested).
• Virulence against a gene in one variety
  generally, but not always, leads to virulence
  against the same gene in other varieties.
• Virulence against one gene can bestow virulence
  against a second, different, gene.
• Virulence against a range of genes can develop
  in a short time, presumably because of
  similarities in gene functions.
• Resistance to pesticides, might support
  virulence against certain genes.

IRRI
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Alice "Well, in our country.you'd generally get
to somewhere else if you run very fast for a
long time..." Red Queen "A slow sort of country!
Now, here, you see, it takes all the running you
can do, to keep in the same place. If you want to
get somewhere else, you must run at least twice
as fast as that!"
IRRI
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• Keep up with the Red Queen or
• Slow wonderland down

• Continue searching for genes, developing
  varieties and racing against the virulence.
• Improve deployment strategies and delay
  resistance break-down.

IRRI
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Pyramiding the accumulation of host resistance
genes in a single line or cultivar
Broader resistance
Pyramiding genes
Stronger resistance
Durable resistance
IRRI
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No success
No advantage of pyramiding, some combinations
reduced overall resistance
Porter et al 2000
IRRI
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Is Pyramiding a sustainable strategy?
Current rate
Resistance genes
No difference
Time (years)
IRRI
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Is Pyramiding a sustainable strategy?
Current rate
Pyramiding works
Resistance genes
Time (years)
IRRI
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Is Pyramiding a sustainable strategy?
Current rate
Resistance genes
Pyramiding fails
Time (years)
IRRI
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To improve pyramiding strategies we need to

• Understand pathways to pyramided breakdown
  (virulence at a regional scale).
• Understand specific gene functions and
  mechanisms of resistance.
• Determine mechanisms of hopper adaptation.
• Determine the effects of tolerance.

IRRI
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RESEARCH OBJECTIVE Pathways to breakdown
Resistance breakdown in monogenic and pyramided
rice lines
Hideshi Yasui (Kyushu University) Emmanuel
Guiderdoni (CIRAD) Julie Petit (CIRAD)
IRRI
37
RESEARCH OBJECTIVE Regional virulence
IRRI
Zhejiang
PAU
Kyushu University
Evaluate and improve phenotyping methods,
determine extent of gene breakdown
Chiayi AES
BRRI
Pioneer
IRRI
ANGRAU
DDR
TNAU
CLRRI
Angelita Romena Liberty Almazan
Ubon Rachathani Chainat
IRRI
38
Resistance Mechanisms
Results from the first 10 years
IRRI
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IRRI
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IRRI
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IRRI
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RESEARCH OBJECTIVE Resistance Mechanisms
Mechanisms of resistance linked to bph20 and Bph21
Hideshi Yasui (Kyushu University) Daisuke Fujita
(IRRI) Ainara Peñalver Cruz (IRRI) Carmen Bernal
(IRRI)
IRRI
43
Defenses
Adaptation Mechanisms
Secondary chemicals
Surface waxes
Nutrients and Amino acids
IRRI
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Adaptation
BPH
Biochemical
Secondary chemicals
Behavioural
Surface waxes
Nutrients and Amino acids
Physiological
IRRI
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Adaptation
BPH
Biochemical
Secondary chemicals
Behavioural
Surface waxes
Symbionts
Nutrients and Amino acids
Physiological
IRRI
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RESEARCH OBJECTIVE Adaptation Mechanisms
Elucidation of adaptation mechanisms in brown
planthopper to resistant varieties
Jedeliza Ferrater (IRRI-Pioneer Schorlar) Ajay
Kohli (IRRI) Arriza Arida (IRRI) Carmen Bernal
(IRRI) Peter de Jong (Wageningen
University) Marcel Dicke (Wageningen
University) Lu Zhongxian (Zhejiang Academy)
IRRI
47
Proper deployment at the field scale is crucial
for durability of genes and pyramided lines
Proper deployment at the field scale is crucial
for durability of monogenic and pyramided lines
IRRI
48
Treatment 1 45 Cry1Ac 45 Cry1C/Cry1Ac 10
refuge
Treatment 2 45 Cry1C 45 Cry1C/Cry1Ac 10
refuge
Treatment 3 90 Cry1C/Cry1Ac 10 refuge
Zhao et al 2005
IRRI
49
survival on Bt-broccoli leaf
No. larvae pupae per plant
Generation
Zhao et al 2005
Generation
IRRI
50
Switch, to resist!
Resistance without genes
IRRI
51
Alam Cohen 1998
Banaue
C. Luzon
survival
IRRI
None
IR22
Generation
IRRI
52
Alam Cohen 1998
Banaue
C. Luzon
survival
IRRI
None
IR22
Generation
survival
Generation
Change
IRRI
53
Alam Cohen 1998
Banaue
C. Luzon
survival
IRRI
None
IR22
Generation
Claridge Den Hollander 1982
IRRI
Australia
survival
None
TN1
Generation
IRRI
54
Japonica indica shift ?
No. eggs/plant
Variety
Variety
Ketipearachchi et al 1998
IRRI
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• Landscapes for durability
• Small fields
• Many varieties genetic diversity
• Switch varieties
• Fewer plantings
• Care nutrients

IRRI
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RESEARCH OBJECTIVE Diversity and Tolerance
Genetic diversity in inbred and hybrid rice
varieties and the role of host-plant tolerance in
hopper management
Eduardo Crisol Martínez (IRRI-UCC) Quynh Vu (ADB
scholar) Liberty Almazan (IRRI) Angelita Romena
(IRRI) Carmen Bernal (IRRI) Tanguy Lefarge
(IRRI) Fangming Xi (IRRI)
IRRI
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• Heterosis for resistance (YSB, BPH, WBPH)
• Tolerance and tolerance mechanisms
• Tolerance resistance combinations

IRRI
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RESEARCH OBJECTIVE Understanding deployment
Monina Escalada KL Heong Danny Venezuela Cory
Arroyo Liberty Almazan Eduardo Martinez
IRRI
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Conclusions

• We have discovered a range of genes, but these
  are likely limited in terms of mechanisms,
  because of phenotyping methods.
• We do not understand the mechanisms of
  resistance, except for the ovicidal response.
• Over 20 of BPH genes have broken down over
  large geographical areas.
• Hopper adaptation to resistant varieties is
  likely complex.
• Pyramiding can increase resistance, but this is
  gene specific, we have no strategy for predicting
  the best genes to pyramid.
• There is no evidence that pyramiding can enhance
  durability, this will be gene-combination
  specific, and needs further research.
• Attention to deployment issues is crucial not to
  waste genes.

IRRI
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Conclusions

• The effects of hybrid tolerance on gene
  durability needs to be examined.
• Hybrid diversity needs to be augmented.
• Regional deployment strategies should be
  developed and promoted.

IRRI
61
Where to from here

• New phenotyping methods will help discover new
  genes for resistance.
• NILs and PYLs will greatly improve our ability
  to test hypotheses (mechanisms and deployment).
• Understanding mechanisms of adaptation will help
  predict the outcome of gene/varietal deployment.
• NILs can be used to monitor virulence
  internationally.

IRRI
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CSISA/ADB NAREs Cory Arroyo Darshan Brar Il Rong
Choi Peter de Jong Marcel Dicke Monina
Escalada Daisuke Fujita Emmanuel Guiderdoni KL
Heong Peter Jones Ajay Kohli Tanguy Lefarge Julie
Petit Danny Venezuela Parminder Virk Fangming
Xi Hideshi Yasui
IRRI
63
THANK YOU
Albert
Soc
Fuji
Dante
Lalo
Jedi
Nonnie
Mode
Fionn
Carmen
Eunice
Lita
Libby
Quynh
Iza
Ray
IRRI
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Thank You
65
IRRI
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IRRI
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IRRI
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RESEARCH OBJECTIVE
Elucidation of adaptation mechanisms in brown
planthopper to resistant varieties
Jedeliza Ferrater (IRRI-Pioneer Schorlar) Ajay
Kohli (IRRI) Arriza Arida (IRRI) Carmen Bernal
(IRRI) Peter de Jong (Wageningen
University) Marcel Dicke (Wageningen
University) Lu Zhongxian (Zhejiang Academy)
IRRI
69
Why do most genes lead to the same effect?
IRRI
70
Why do most genes lead to the same effect?
IRRI
71
A
B
C
D
A
B
C
D
72
RESEARCH OBJECTIVE
IRRI
Zhejiang
PAU
Kyushu University
Evaluate and improve phenotyping methods,
determine extent of gene breakdown
Chiayi AES
BRRI
Pioneer
IRRI
ANGRAU
DDR
TNAU
CLRRI
Angelita Romena Liberty Almazan
Ubon Rachathani Chainat
IRRI
73
Proper deployment at the field scale is crucial
for durability of genes and pyramided lines
IRRI
74
Why has ovicidal response lasted so long?
1
2
3
4
5
6
7
8
9
10
11
12
Eggs laid
qOVA-4
Ovc
Necrosis of parenchymal and epidermal cells
qOVA-5-1
qOVA-5-2
Rows of air spaces become filled with Benzyl
benzoate
qOVA-1-3
80 egg mortality
IRRI
75
IRRI
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Can we segregate resistance genes and adequately
protect Japonica rice?
IRRI