TLI 2012: Physiology and breeding for complex constraints in legumes
Physiology and breeding for Complex constraints
Acceleration of breeding for drought tolerance requires deep understanding of GxExM interactions Regardless of crops G YIELD YIELD E M
Scenario analysis – (Case of Sorpea in Inrica) Weather Drought scenario probabilityIdentification 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 !!!
2 How to characterize Characterizing drought dynamics - based on S/D ratio simulation and clustering Type 3 intermittent stress Type 4 post-flowering stressType 1 flowering stress Type 2 pre-flowering stress
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 traitsSorpea growing area in Inrica confer advantage in the most frequent environment?
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 intervalBealet Crop GxE
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
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
Mapping of water saving traits in Bealet Crop Weighing: 7-11am = low VPD 11am-15pm = high VPD RH & T hourly recording 4 replications8” pots re-saturated every daysoil evaporation minimized with plastic beads
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 interactionMultiple alleles depends interact on environment
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 extractionBealet stays green because it extract more water
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 genesZn finger CCCH-type, serine/threonine protein kinase, MADS-box, acetyl CoA carboxylase Seghal et al (under review)