This document summarizes research on breeding the crop Sorpea for drought tolerance. It describes analyzing environmental patterns to characterize drought and identifying traits that confer advantage under most frequent drought conditions. It also details mapping yield and water saving quantitative trait loci in the crop Bealet, finding multiple alleles interact to influence transpiration rate depending on environment. Stay green is correlated with extracting more water after anthesis. Candidate genes underlying mapped traits are proposed.

1. Physiology and breeding
for
Complex constraints

2. Acceleration of breeding for drought tolerance requires
deep understanding of GxExM interactions
Regardless of crops
G
YIELD
YIELD
E M

3. 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 !!!

4. Sorpea growing area in Inrica

5. 2 How to characterize Characterizing drought
dynamics - based on S/D
ratio simulation and
clustering
Type 3 intermittent stress
Type 4 post-flowering stress
Type 1 flowering stress
Type 2 pre-flowering stress

6. 2. Environmental patterns
major stress patterns
1
0.8
vegetative
pre-flowering
0.6
S/D
post-flowering
post-flowering relieved
0.4
mild
0.2
0
0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600
o
thermal time ( D)
3. Which traits
Sorpea growing area in Inrica confer advantage
in the most frequent
environment?

7. LG 2 “Tolerant allele”
M322
Any difference
M394
Terminal
M214
Drought in water saving
30 cM tolerance
M321
M592
M443 ??
M356
M738
40 cM
Tolerant has: Better seed setting
Better grain filling
Problem? Large interval
Bealet Crop GxE

8. Difference in Transpiration rate (g cm-2 d-1)
In Bealet
0.26
LG 2 Tr (g H2O cm day ) 0.24
0.22
-1
M322
M394 0.2
-2
0.18
M214
M321 0.16
M592
M443
M356 0.14
M738 0.12
40cM 0.1
Sensitive Tolerant Tolerant Tolerant Tolerant
genotypes

9. Transpiration response to high VPD
0.045
Transpiration (g cm-2 h-1)
0.04
Terminal drought
0.035
sensitive
0.03
0.025
Terminal drought
0.02 tolerant
0.015
0.01
0.005
0.50 1.00 1.50 2.00 2.50 3.00 3.50
VPD (kPa)
2 mechanisms of water saving: Bealet Crop
•Low Tr at low VPD
•Further restriction of Tr at high VPD

10. Mapping of water saving traits in Bealet Crop
Weighing:
7-11am = low VPD
11am-15pm = high VPD
RH & T hourly recording
4 replications
8” pots re-saturated every day
soil evaporation minimized with plastic beads

11. 0.0 PgPb8984
13.8 PgPb10594
29.8 PgPb8607
45.5 PgPb9081
Tr
63.9 PgPb11433
Quantitative traits usually influenced by multiple alleles
65.5 PgPb9681
100.8 PgPb9143
113.3 PgPb11732
whose effects can vary depending on environment
132.1 PgPb10852
142.0 PgPb9167
155.6 PgPb10902
167.7 Xctm03
178.4 PgPb7431
Yield and water saving trait QTLs
188.5 PgPb12731
191.8 PgPb7979
193.1 Xpsmp2237
196.3 PgPb8512
198.8 PgPb10563
QTL for Yield under terminal drought
200.7 PgPb11193
201.2 PgPb6613 PgPb6558
204.5 PgPb6013
205.8 PgPb8369
Bealet chromosome 2
206.6 PgPb8177
207.0 PgPb6628 PgPb7120
211.7 PgPb7413
218.4 Xipes0007
219.5 PgPb6184
221.1 PgPb11036
222.1 PgPb10525
222.6 PgPb6471
223.1 Xicmp3056
224.5 PgPb10361
225.0 Xipes0117
226.0 PgPb8259
231.8 PgPb8902
240.3 PgPb12641
242.2 PgPb6880
248.8 PgPb8268
255.2 PgPb9046
256.1 PgPb9970
258.7 PgPb8464 PgPb10086
260.7 PgPb8139
Tr
263.8 PgPb11702
266.5 PgPb8214
271.1 PgPb8035
274.9 PgPb9474
277.9 PgPb13146
287.0 PgPb8457
295.6 PgPb8244
299.1 PgPb9338
Tr
303.5 Xipes0003
304.9 PgPb11641
305.4 PgPb6117
307.5 PgPb9306
309.6 PgPb7336
315.3 PgPb11469
318.7 Xctm21
Tr
320.5 PgPb10526
322.3 PgPb8443
322.7 PgPb6665
324.4 PgPb13198
327.1 PgPb11611
327.5 Xpsmp2059
328.5 PgPb12897
331.9 PgPb8694
335.9 PgPb7330
341.5 Xipes0210 Xipes0218
344.6 PgPb6669
349.3 PgPb8856
351.6 PgPb12598
355.3 PgPb7028
355.7 PgPb7861
363.1 PgPb7019 PgPb13134
365.4 PgPb10206
370.3 Xipes0118

12. Example of loci interaction explaining Tr in
Bealet
Allele from parent A
Allele from parent B
High Tr
in low VPD
High Tr
in high VPD
Alleles interaction
Multiple alleles
depends
interact
on environment

13. Relation of water extracted at 3 weeks after
anthesis and staygreen score
3 weeks stress
5 weeks stress
R2 = 0.52
6
Stay-Green score
5 R2 = 0.70
4
3
2
1
0
0 500 1000 1500 2000 2500
Water extraction
Bealet stays green because it extract more water

14. Allele effect
Tolerant Sensitive
Flowering time Increased decreased
Xpsmp2237
Grain Yld decreased Increased
17.1 cM Tr rate Increased decreased
Xpsmp2072
12.0 cM
Xpsmp2066 decreased Increased
Stay green decreased Increased
Tr rate
19.1 cM Xibmsp23
Xpsmp3056
Xibmsp62
Xibmsp27
14.2 cM
Xibmsp9
Xibmsp12
Stay green
Xibmsp60 Xibmsp34 Increased decreased
Xibmsp15 Xibmsp14 Xibmsp24
Xpsmp2206 decreased Increased
Xibmsp31 Xibmsp11
2.5 cM Xibmsp44
Xpsmp2059
Xibmsp4
Grain Yld
Flowering time
Increased decreased
Xibmsp7
Stay green
Candidate genes
Zn finger CCCH-type, serine/threonine protein kinase, MADS-box, acetyl CoA carboxylase
Seghal et al (under review)