GRiSPIntegrating Physiology, Crop

Modeling and Geneticsto Tackle Thermal

Stresses inRice:

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

GRiSPHistory: The 1990s research at WARDA Thermal constraints to irrigated rice in Senegal

Effect of sowing date on crop duration and sterility

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

Days to flowering

% sterility % sterility

Tw(min) at bootingSowing dateSowing date

Þ 1995 development of RIDEV predicting phenology and thermal sterility as risk analysis and decision aide for cropping calendars

GRiSPNew study on rice phenology and sterility responses to T

(Thesis of Cecile Julia & ongoing CIRAD/IRRI/CCAFS project)

Emphasis on microclimate 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

NEW

NEW

GRiSP

Date01/08 11/08 21/08 31/08 10/09 20/09 30/09

Tem

pera

ture

(°C

)

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Date

01/03 11/03 21/03 31/03 10/04 20/04 30/04 T

empe

ratu

re (

°C)

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Tair Max Tair Min Twater max Twater min

Date

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

Tem

pera

ture

(°C

)

8

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Date10/05 20/05 30/05 09/06 19/06

Tem

pera

ture

(°C

)

8

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36

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44

France - Temperate Summer 2009

VP

D (

KP

a)

012345

Senegal - Cold and dry season 2010

VP

D (

KP

a)

012345

Senegal - Hot and dry season 2010

VP

D (

KP

a)

012345

Philippines - Hot and dry season 2009

VP

D (

KP

a)

012345

Scope of study:

4 genotypesIR64IR72Sahel108Chomrong(N22 failed)

4 environmentsDS PhilippinesHDS SenegalCDS SenegalTemp. summer France

Traits observedPhenologyTOAPanicle transp. cooling

GRiSP Results

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

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

GRiSP

Pan1Pan2

Flagleaf1

Flagleaf2

Pan3

Pan4

Flagleaf3

Flagleaf4

Leaf5

ca. 4900 IR observations on in-situ panicle TMicroclimate recording% sterility observed at maturity

Panicle temperature: IR imagery in the field

GRiSP

0 1 2 3 4 5 6 7-4

-2

0

2

4

6

8

10

12

14

f(x) = 1.45344554944651 x − 0.991079944085128R² = 0.790388621127665

c

VPD (kPa)

TD

=T

a-T

p (

°C)

Relative humidity or vapor pressure deficit is the main determinant of Ta-Tp difference

Example: Senegal cool-dry season

Panicle warmer than air

Panicle cooler than air

Humid Arid

TD (predicted) [°C]

-4 -2 0 2 4 6 8 10 12 14

TD

(ob

serve

d) [°C

]

-4

-2

0

2

4

6

8

10

12

14

Senegal cool-dryseasonSenegal hot-dryseasonFrance summer

1:1

Model prediction (sim:obs)

GRiSP

PHIL_DS SEN_HS SEN_CS FR_HS22

24

26

28

30

32

(b)

Site

Tem

per

atu

re (

°C)

Air and Panicle Temperature at TOA (calculated)

The panicle is warmest not in the hottest, but in the most humid environment

Phils Sen.-hot Sen.-cool France

GRiSP

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

PHIL_DS SEN_HS SEN_CS FR_HS0

10

20

30

40

50

60

70

80

90

100(c)

Chomrong IR64 S108 IR72

Site

Ste

rili

ty (

%)

Temperature induced spikelet sterility

Phils Sen.-hot Sen.-cool France

GRiSP

PHIL_DS SEN_HS SEN_CS FR_HS

40

60

80

100

120

140

160

Chomrong IR64 S108 IR72 Last grain

Neck node

Site

Pa

nic

le e

xs

ert

ion

(%

)

(b)

Incomplete panicle exertion occurred in cold-night environments explained some of observed sterility

Sterile fraction of paniclecaused by non-exertion

Phils Sen.-hot Sen.-cool France

GRiSP

12 14 16 18 20 22 24 26 280

10

20

30

40

50

60

70

80

90

100 Phil-ds Sen-hs

Sen-cs Fr-hs

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

Ste

rili

ty (

%)

Chomrong

2. Chilling effect at microspore stage on sterility (Tmeristem = Twater)

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

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

Use of RIDEV for Phenomics/GWAS

GRiSP

Thank youMerciSalamat po