Physiology and breeding

for

Complex constraints

YIELD

E

YIELD

G

Acceleration of breeding for drought tolerance requires deep understanding of GxExM interactions

Regardless of crops

M

Scenario analysis – (Case of Sorpea in Inrica) Weather

Drought scenario probability

Identification of key traits – (Case of Bealet in Amefrica) what trait

mapping loci interactions

Any resemblance to any crop having existed can only be coincidental

Nevertheless, data presented are real !!!

Sorpea growing area in Inrica

Characterizing drought dynamics - based on S/D ratio simulation and clustering

Type 3 intermittent stress

Type 2 pre-flowering stress

Type 1 flowering stress

Type 4 post-flowering stress

2 How to characterize

major stress patterns

0

0.2

0.4

0.6

0.8

1

0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600

thermal time (oD)

S/D

vegetative

pre-flowering

post-flowering

post-flowering relieved

mild

3. Which traits confer advantage

in the most frequent environment?

2. Environmental patterns

Sorpea growing area in Inrica

Tolerant has: Better seed setting Better grain filling

Any difference in water saving

??

LG 2 M322

M394

M214

M321 M592 M443

M356

M738

Terminal Drought

tolerance

“Tolerant allele”

40 cM

30 cM

Bealet Crop Problem? Large interval GxE

Difference in Transpiration rate (g cm-2 d-1) In Bealet

LG 2 M322

M394

M214

M321 M592 M443

M356

M738

40 cM 0.1

0.12

0.14

0.16

0.18

0.2

0.22

0.24

0.26

Sensitive Tolerant

genotypes

Tr

(g H

2O

cm

-2 d

ay -1

)

Tolerant Tolerant Tolerant

Terminal drought sensitive

Terminal drought tolerant

0.005

0.01

0.015

0.02

0.025

0.03

0.035

0.04

0.045

0.50 1.00 1.50 2.00 2.50 3.00 3.50

VPD (kPa)

Tran

sp

irati

on

(g

cm

-2 h

-1)

2 mechanisms of water saving: •Low Tr at low VPD •Further restriction of Tr at high VPD

Transpiration response to high VPD

Bealet Crop

4 replications

RH & T hourly recording

Weighing:

7-11am = low VPD

11am-15pm = high VPD

8” pots re-saturated every day

soil evaporation minimized with plastic beads

Mapping of water saving traits in Bealet Crop

PgPb8984

0.0

PgPb10594

13.8

PgPb8607

29.8

PgPb9081

45.5

PgPb11433

63.9

PgPb9681

65.5

PgPb9143

100.8

PgPb11732

113.3

PgPb10852

132.1

PgPb9167

142.0

PgPb10902

155.6

Xctm

03

167.7

PgPb7431

178.4

PgPb12731

188.5

PgPb7979

191.8

Xpsm

p2237

193.1

PgPb8512

196.3

PgPb10563

198.8

PgPb11193

200.7

PgPb6613

PgPb6558

201.2

PgPb6013

204.5

PgPb8369

205.8

PgPb8177

206.6

PgPb6628 PgPb7120

207.0

PgPb7413

211.7

Xip

es0007

218.4

PgPb6184

219.5

PgPb11036

221.1

PgPb10525

222.1

PgPb6471

222.6

Xic

mp3056

223.1

PgPb10361

224.5

Xip

es0117

225.0

PgPb8259

226.0

PgPb8902

231.8

PgPb12641

240.3

PgPb6880

242.2

PgPb8268

248.8

PgPb9046

255.2

PgPb9970

256.1

PgPb8464 PgPb10086

258.7

PgPb8139

260.7

PgPb11702

263.8

PgPb8214

266.5

PgPb8035

271.1

PgPb9474

274.9

PgPb13146

277.9

PgPb8457

287.0

PgPb8244

295.6

PgPb9338

299.1

Xip

es0003

303.5

PgPb11641

304.9

PgPb6117

305.4

PgPb9306

307.5

PgPb7336

309.6

PgPb11469

315.3

Xctm

21

318.7

PgPb10526

320.5

PgPb8443

322.3

PgPb6665

322.7

PgPb13198

324.4

PgPb11611

327.1

Xpsmp2059

327.5

PgPb12897

328.5

PgPb8694

331.9

PgPb7330

335.9

Xip

es0210

Xip

es0218

341.5

PgPb6669

344.6

PgPb8856

349.3

PgPb12598

351.6

PgPb7028

355.3

PgPb7861

355.7

PgPb7019

PgPb13134

363.1

PgPb10206

365.4

Xip

es0118

370.3

Tr Tr Tr

Bealet chromosome 2

Quantitative traits usually influenced by multiple alleles whose effects can vary depending on environment

Tr

QTL for Yield under terminal drought

Yield and water saving trait QTLs

Multiple alleles interact

Alleles interaction depends

on environment

High Tr in high VPD

High Tr in low VPD

Allele from parent A

Allele from parent B

Example of loci interaction explaining Tr in Bealet

Relation of water extracted at 3 weeks after anthesis and staygreen score

R2 = 0.52

R2 = 0.70

0

1

2

3

4

5

6

0 500 1000 1500 2000 2500

Water extraction

Sta

y-G

ree

n s

co

re5 weeks stress

3 weeks stress

Bealet stays green because it extract more water

Xpsmp2237

Xpsmp2072

17.1 cM

Xpsmp2066

12.0 cM

Xpsmp3056

19.1 cM

Xpsmp2206

14.2 cM

Xpsmp2059

2.5 cM

Grain Yld Flowering time

Grain Yld

Allele effect

Xibmsp44

Xibmsp4

Xibmsp7

Xibmsp60 Xibmsp34 Xibmsp14 Xibmsp24 Xibmsp31 Xibmsp11

Xibmsp62 Xibmsp27 Xibmsp9 Xibmsp12

Xibmsp15

Xibmsp23

Tolerant Sensitive

Increased decreased

decreased Increased

Flowering time

Increased decreased

decreased Increased

Stay green decreased Increased

Increased decreased

Tr rate Increased decreased

Tr rate decreased Increased

Stay green

Candidate genes Zn finger CCCH-type, serine/threonine protein kinase, MADS-box, acetyl CoA carboxylase

Stay green

Seghal et al (under review)