GRiSP

Integrating Physiology, Crop
Modeling and Genetics
to Tackle Thermal
Stresses in
Rice:

The RIDEV Approach
Michael Dingkuhn (IRRI/CIRAD), Julie Mae
Pasuquin (IRRI), Cecile Julia (CIRAD), Richard
Pasco (IRRI), Jean-Christophe Soulie (CIRAD)

funded by GIZ, AfricaRice, CCAFS and CIRAD

Context of GRiSP Global Rice Phenotyping
Network
GRiSP Rationale
 Thermal adaptation is fundamental for agro-ecological fit
 Temperature governs rice phenology and spikelet fertility

 Climate change is changing thermal environments
 Accuracy of crop models is still poor re: thermal effects
 We need…
 Better predictive tools to map climate change impact
 Better understanding of adaptive traits: Physiology &
Genetics
GRiSP

History: The 1990s research at WARDA
Thermal constraints to irrigated rice in Senegal
Effect of sowing date on crop duration and sterility

Days to flowering

• Thermal and photoperiod effects on phenology
• Chilling causes spikelet sterility
% sterility

Sowing date

Sowing date

% sterility

Tw(min) at booting

1995 development of RIDEV predicting phenology and thermal
sterility as risk analysis and decision aide for cropping calendars
New study on rice phenology and sterility
GRiSP
responses to T
(Thesis of Cecile Julia & ongoing CIRAD/IRRI/CCAFS project)

 Emphasis on microclimate


NEW 
NEW 

Meristem T => phenology
Floodwater T => chilling stress at microspore stage
Panicle T => heat stress at anthesis
Time of day of anthesis (TOA)

 RIDEV v.2 to characterize genetic diversity
Philippines - Hot and dry season 2009

36

32
28
24
20
16
12
8
01/03

32
28
24
20
16
12

11/03

21/03

31/03

10/04

20/04

8
10/05

30/04

20/05

Senegal - Cold and dry season 2010

44
40

36

36

Temperature (°C)

Phenology
TOA
Panicle transp. cooling

19/06

France - Temperate Summer 2009

40

Temperature (°C)

Traits observed

5
4
3
2
1
0

44

09/06

VPD (KPa)

4 environments

30/05

Date

Date

DS Philippines
HDS Senegal
CDS Senegal
Temp. summer France

VPD (KPa)

36

5
4
3
2
1
0

40

Temperature (°C)

Temperature (°C)

IR64
IR72
Sahel108
Chomrong
(N22 failed)

44

40

4 genotypes

44

5
4
3
2
1
0

VPD (KPa)

Scope of study:

Senegal - Hot and dry season 2010
VPD (KPa)

GRiSP

5
4
3
2
1
0

32
28
24
20
16

32
28
24
20
16

12

12

8
15/01 25/01 04/02 14/02 24/02 06/03 16/03 26/03

Date

8
01/08

Tair Max
Tair Min
Twater max
Twater min

11/08

21/08

31/08

Date

10/09

20/09

30/09
GRiSP

Results

Time of day of anthesis (TOA)
shows adaptive plasticity
Warm nights advance TOA =>
Escape from midday heat
Humid days advance TOA =>
Escape from heat caused by absence
of transpiration cooling

Mean air temp (min) during last 7d before anthesis (oC)
GRiSP

Panicle temperature: IR imagery in the field
Pan2

Pan1

Flagleaf4

Flagleaf1
Flagleaf2

Flagleaf3

Leaf5
Pan3

Pan4

ca. 4900 IR observations on in-situ panicle T
Microclimate recording
% sterility observed at maturity
Relative humidity or vapor pressure deficit is the
main determinant of Ta-Tp difference

GRiSP

14
Senegal cool-dry
season
Senegal hot-dry
season
France summer

12

14

10

TD (observed) [°C]

c
Example: Senegal cool-dry season

12

TD=Ta-Tp (°C)

10
y = 1.45x - 0.99
R² = 0.79

1:1

8
6
4
2
0
-2

8

-4
-4

6

-2

0

2
4
6
8
TD (predicted) [°C]

10

12

14

Model prediction (sim:obs)

4

Panicle cooler
than air

2
0

Panicle warmer
than air

-2
-4
0

1

Humid

2

3

4

VPD (kPa)

5

6

Arid

7
GRiSP The panicle is warmest not in the hottest, but in the
most humid environment
(b)
Air and Panicle Temperature at TOA (calculated)

32

Temperature (°C)

30

28

26

24

22
PHIL_DS
Phils

SEN_HS
Sen.-hot

Site

SEN_CS
Sen.-cool

FR_HS
France
Temperature induced spikelet sterility
Chomrong
100

IR64

S108

IR72

(c)

90
80

Sterility (%)

GRiSP

70

Disaggregate observed
sterility into its components
 Incomplete panicle exertion
 Chilling at microspore stage
 Heat at anthesis (at TOA)

60
50
40
30

20
10
0

Phils
PHIL_DS Sen.-hot
SEN_HS Sen.-cool
SEN_CS

Site

France
FR_HS
Incomplete panicle exertion

GRiSP

 occurred in cold-night environments
 explained some of observed sterility

Chomrong

Panicle exsertion (%)

160

IR64

S108

IR72

Last grain

Neck node

(b)

140

120

100

Sterile
fraction of
panicle
caused by
non-exertion

80

60

40
PHIL_DS
Phils

SEN_HS
SEN_CS
Sen.-hot
Sen.-cool
Site

FR_HS
France
GRiSP 2. Chilling effect at microspore
stage on sterility
(Tmeristem = Twater)
100

Phil-ds
Sen-cs

90

Sen-hs
Fr-hs

Sterility (%)

80
70
60
50
40

Chomron

30
20

10
0
12

14

16

18

20

22

24

26

28

T water (min) at microspore stage (°C)

3. Heat effect at flowering
stage on sterility (Tp at TOA)
GRiSP

Conclusions from experimental study
Rice has highly effective adaptations to thermal stresses:
 Avoidance
 Transpiration cooling of panicle
 Good panicle exertion (long peduncle)
 Escape
 Time of day of anthesis (TOA) and its adaptive plasticity
 Tolerance
 To cold, as shown for cv. Chomrong
 Heat tolerant check cv. N22 failed (seed problems)

Heat stress more likely in warm-humid than hot-dry climates!
GRiSP A new modeling tool RIDEV V.2
 Simulator of…
 Phenology incl. microclimate & photoperiod effects
 G and E effects on TOA
 Sterility caused by…
 Chilling effects on microsporogenesis (water Tmin)
 Chilling effects on panicle exertion (air Tmin)
 Heat effects on pollination (Tpanicle at TOA)
 Prediction (forward mode)
 Climate change impact mapping, plant type optimization
 Agronomy (crop calendar; optimization)
 Heuristic parameterization of genotypes (reverse mode)
 Phenomics (extraction of genotypic parameter values
from experimental data)
GRiSP

Outlook
Use of RIDEV for Phenomics/GWAS


Indica GWAS panel (>200 acc., ORYTAGE project)



Field-phenotyped for phenology and sterility in 12 environments:
 6 sowing dates in Senegal
 3 altitudes x 2 years in Madagascar



Extraction of genotypic response parameters across
environments (Heuristics):
 Cardinal temperatures Tb and To
 Thermal duration of phenological phases
 Photoperiod-sensitivity
 Chilling sensitivity of microsporogenesis
 Chilling sensitivity of panicle exertion
 Heat sensitivity of anthesis



Association study using GBS and 700K Oryza SNP chip
GRiSP

Thank you
Merci
Salamat po

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Th2_Integrating Physiology, Crop Modeling and Genetics

  • 1. GRiSP Integrating Physiology, Crop Modeling and Genetics to Tackle Thermal Stresses in Rice: The RIDEV Approach Michael Dingkuhn (IRRI/CIRAD), Julie Mae Pasuquin (IRRI), Cecile Julia (CIRAD), Richard Pasco (IRRI), Jean-Christophe Soulie (CIRAD) funded by GIZ, AfricaRice, CCAFS and CIRAD Context of GRiSP Global Rice Phenotyping Network
  • 2. GRiSP Rationale  Thermal adaptation is fundamental for agro-ecological fit  Temperature governs rice phenology and spikelet fertility  Climate change is changing thermal environments  Accuracy of crop models is still poor re: thermal effects  We need…  Better predictive tools to map climate change impact  Better understanding of adaptive traits: Physiology & Genetics
  • 3. GRiSP History: The 1990s research at WARDA Thermal constraints to irrigated rice in Senegal Effect of sowing date on crop duration and sterility Days to flowering • Thermal and photoperiod effects on phenology • Chilling causes spikelet sterility % sterility Sowing date Sowing date % sterility Tw(min) at booting 1995 development of RIDEV predicting phenology and thermal sterility as risk analysis and decision aide for cropping calendars
  • 4. New study on rice phenology and sterility GRiSP responses to T (Thesis of Cecile Julia & ongoing CIRAD/IRRI/CCAFS project)  Emphasis on microclimate   NEW  NEW  Meristem T => phenology Floodwater T => chilling stress at microspore stage Panicle T => heat stress at anthesis Time of day of anthesis (TOA)  RIDEV v.2 to characterize genetic diversity
  • 5. Philippines - Hot and dry season 2009 36 32 28 24 20 16 12 8 01/03 32 28 24 20 16 12 11/03 21/03 31/03 10/04 20/04 8 10/05 30/04 20/05 Senegal - Cold and dry season 2010 44 40 36 36 Temperature (°C) Phenology TOA Panicle transp. cooling 19/06 France - Temperate Summer 2009 40 Temperature (°C) Traits observed 5 4 3 2 1 0 44 09/06 VPD (KPa) 4 environments 30/05 Date Date DS Philippines HDS Senegal CDS Senegal Temp. summer France VPD (KPa) 36 5 4 3 2 1 0 40 Temperature (°C) Temperature (°C) IR64 IR72 Sahel108 Chomrong (N22 failed) 44 40 4 genotypes 44 5 4 3 2 1 0 VPD (KPa) Scope of study: Senegal - Hot and dry season 2010 VPD (KPa) GRiSP 5 4 3 2 1 0 32 28 24 20 16 32 28 24 20 16 12 12 8 15/01 25/01 04/02 14/02 24/02 06/03 16/03 26/03 Date 8 01/08 Tair Max Tair Min Twater max Twater min 11/08 21/08 31/08 Date 10/09 20/09 30/09
  • 6. GRiSP Results Time of day of anthesis (TOA) shows adaptive plasticity Warm nights advance TOA => Escape from midday heat Humid days advance TOA => Escape from heat caused by absence of transpiration cooling Mean air temp (min) during last 7d before anthesis (oC)
  • 7. GRiSP Panicle temperature: IR imagery in the field Pan2 Pan1 Flagleaf4 Flagleaf1 Flagleaf2 Flagleaf3 Leaf5 Pan3 Pan4 ca. 4900 IR observations on in-situ panicle T Microclimate recording % sterility observed at maturity
  • 8. Relative humidity or vapor pressure deficit is the main determinant of Ta-Tp difference GRiSP 14 Senegal cool-dry season Senegal hot-dry season France summer 12 14 10 TD (observed) [°C] c Example: Senegal cool-dry season 12 TD=Ta-Tp (°C) 10 y = 1.45x - 0.99 R² = 0.79 1:1 8 6 4 2 0 -2 8 -4 -4 6 -2 0 2 4 6 8 TD (predicted) [°C] 10 12 14 Model prediction (sim:obs) 4 Panicle cooler than air 2 0 Panicle warmer than air -2 -4 0 1 Humid 2 3 4 VPD (kPa) 5 6 Arid 7
  • 9. GRiSP The panicle is warmest not in the hottest, but in the most humid environment (b) Air and Panicle Temperature at TOA (calculated) 32 Temperature (°C) 30 28 26 24 22 PHIL_DS Phils SEN_HS Sen.-hot Site SEN_CS Sen.-cool FR_HS France
  • 10. Temperature induced spikelet sterility Chomrong 100 IR64 S108 IR72 (c) 90 80 Sterility (%) GRiSP 70 Disaggregate observed sterility into its components  Incomplete panicle exertion  Chilling at microspore stage  Heat at anthesis (at TOA) 60 50 40 30 20 10 0 Phils PHIL_DS Sen.-hot SEN_HS Sen.-cool SEN_CS Site France FR_HS
  • 11. Incomplete panicle exertion GRiSP  occurred in cold-night environments  explained some of observed sterility Chomrong Panicle exsertion (%) 160 IR64 S108 IR72 Last grain Neck node (b) 140 120 100 Sterile fraction of panicle caused by non-exertion 80 60 40 PHIL_DS Phils SEN_HS SEN_CS Sen.-hot Sen.-cool Site FR_HS France
  • 12. GRiSP 2. Chilling effect at microspore stage on sterility (Tmeristem = Twater) 100 Phil-ds Sen-cs 90 Sen-hs Fr-hs Sterility (%) 80 70 60 50 40 Chomron 30 20 10 0 12 14 16 18 20 22 24 26 28 T water (min) at microspore stage (°C) 3. Heat effect at flowering stage on sterility (Tp at TOA)
  • 13. GRiSP Conclusions from experimental study Rice has highly effective adaptations to thermal stresses:  Avoidance  Transpiration cooling of panicle  Good panicle exertion (long peduncle)  Escape  Time of day of anthesis (TOA) and its adaptive plasticity  Tolerance  To cold, as shown for cv. Chomrong  Heat tolerant check cv. N22 failed (seed problems) Heat stress more likely in warm-humid than hot-dry climates!
  • 14. GRiSP A new modeling tool RIDEV V.2  Simulator of…  Phenology incl. microclimate & photoperiod effects  G and E effects on TOA  Sterility caused by…  Chilling effects on microsporogenesis (water Tmin)  Chilling effects on panicle exertion (air Tmin)  Heat effects on pollination (Tpanicle at TOA)  Prediction (forward mode)  Climate change impact mapping, plant type optimization  Agronomy (crop calendar; optimization)  Heuristic parameterization of genotypes (reverse mode)  Phenomics (extraction of genotypic parameter values from experimental data)
  • 15. GRiSP Outlook Use of RIDEV for Phenomics/GWAS  Indica GWAS panel (>200 acc., ORYTAGE project)  Field-phenotyped for phenology and sterility in 12 environments:  6 sowing dates in Senegal  3 altitudes x 2 years in Madagascar  Extraction of genotypic response parameters across environments (Heuristics):  Cardinal temperatures Tb and To  Thermal duration of phenological phases  Photoperiod-sensitivity  Chilling sensitivity of microsporogenesis  Chilling sensitivity of panicle exertion  Heat sensitivity of anthesis  Association study using GBS and 700K Oryza SNP chip

Editor's Notes

  • #4: Graph 1:Sowing date in the Sahel strongly affects crop duration even in modern varieties (e.g., WS vs. Hot-dry season)Graph 2:Sowing in September-November caused near-total sterility (cold). Sterility sometimes also high for sowing in Feb-Mar (heat)Graph 3:Much of the sterility could be explained with minimum T(water) at booting stage (ca. 2 wk before flowering)RIDEV:A 1st model simulating this was developed in 1995 and extensively used by NARS and ARC for risk analyses and crop calendar planning
  • #5: Weakness of old RIDEV:No consideration of TOA and T(panicle)Need for new study focusing on micro climate and heat
  • #7: Important:This is hours after sunrise- T-dependent shift in TOA by up to 4h (e.g., from 9 am (warm) to 1 pm (cool))
  • #8: Manual scene takingManual image analysisLongitudinal and transversal gradient analyses
  • #9: Observations at different times of dayRH or VPD is main determinant of Panicle-air T differenceRs, wind, solar angle etc. also have effectsThese effects were combined in a multiple regression model and used in RIDEV to predict panicle T for any given time of day.That model was compared with a mechanistic energy balance model (IM2PACT, Japan) which gave the same results
  • #11: Highest spikelet sterility in Senegal cool seasonLowest in Senegal hot season (!)We wanted to disaggregate this sterility into 3 different fractions (causes)
  • #12: Panicle exertion – relative position of the panicle neck node to the top of the enclosing leaf sheath (broken line); relative position of lowest spikelets on the panicle (solid line)Short-strawed high yielding rice – increased risk of incomplete panicle exertion (short peduncles)Sahel 108 – selected by breeders in Senegal aiming at avoiding bird damage and improving light use through panicles hidden deep in the canopy
  • #13: Graph 1:At minimum water temperature below 18-20 oC, sterility increases, except the tolerantChomrongCold tolerance: involves anti-oxidative enzymes protecting the tissues, production of more pollen to increase probability of successful pollinationGraph 2:If cases of cold-sterility are taken out of the analysis, the remaining cases show a good correlation of sterility with heat at anthesis. But only if PANICLE T (not air!) and TOA (not Tmin or Tmax or Tmean) are used as reference.