molecular breeding & genetic engineering for drought ...super7/30011-31001/30321.pdf · mas...

Molecular breeding & genetic engineering

for drought tolerance

What scope ?

Vincent VadezICRISAT

ICRISAT in shortInternational Crops Research Institute for the Semi-Arid Tropics

5 mandate crops: Chickpea, pigeonpea, groundnutPearl millet, sorghum

1.3 Billions people in drought-prone areas (India/Africa)Drought is a major research focus for ICRISAT

Drought research at ICRISAT

Today’s presentation

MAS (pearl millet, sorghum)- PNHI and staygreen

QTL identification (chickpea)-Roots

QTL identification + Transgenics (groundnut)- Transpiration Efficiency (TE)

MAS for pearl millet

Pearl millet line-source irrigation experiment, summer drought nursery, ICRISAT-Patancheru


LG 2M 322

M 394

M 214

M 321M 592 M 443M 356

M 738

Panicle no.2

Biomass yield2

Stover yield2

Drought tolerance

per se

Stress performance

Stressperformance

“H 77 alle le” “PRLT allele”

40 cM

Grain yield2

100-grain mass3

Harvest index3

Biomass yield1

Grain yield3

100-grain mass3

Harvest index3

Panicle grain no.1

Leaf rolling1

A major terminaldrought tolerance QTL on LG2

Gra

in y

ield

(g m

-2)

250

270

290

310

330

350

370

390

410

430

450

100% 92% 83% 75% 66% 58% 49% 41% 32%

Percentage of non-stress irrigation

ICMR 01029PRLT 2/89-33H 77/833-2


Near-isogenic pearl millet hybrids differing in terminal drought tolerance

843A x ICMR 01029

843A x H77 (=HHB 67): Smaller percentage of florets setting grains: Poorer grain filling


Neutron probe observations in the field

20

25

30

35

Moi

stur

e at

90-

105

cm

PRLT2/89-3H77/833-2

ICMR 01029

Dates of sampling

Grain filling

Tolerant material deplete more moisture at deeper layers

MAS for sorghum

0

20

40

60

80

100

120

1 2 3 4 5 6 7 8 9

Weeks from flowering

% G

reen

leaf

are

a

ISIAP DoradoIDSG 02034IDSG 02368

Staygreen Senescent

Maintenance of a green leaf areaUnder terminal drought

MAS for sorghum

Evaluation in the field under terminal drought

0.600

0.650

0.700

0.750

0.800

0.850

0.900

0.950

1.000

0.000 0.100 0.200 0.300 0.400 0.500 0.600 0.700 0.800

Rel

ativ

e 10

0 G

rain

Mas

s

R2 = 0.72

Relative %GLA

Roots – staygreen contribute to better grain filling

MAS for sorghum

ISIAP Dorado

Range in IL ILs >Dorado

ILs <Dorado

Harvest index (%) 40.6 28.3 − 44.4 2 11Grain yield (g plant-1) 54.2 34.5 − 57.4 0 13Stover yield (g plant-1) 65.8 41.4 − 77.0 1 5

NIRS-predicted NDM and digestibility values of stoverEntry name NDM, % of

R 16 meanDigestibility,

% of R 16 mean

RSG 03061 147% 108%

RSG 03123 137% 118%

Need to advance more generations of backcrosses

MAS for sorghum

6 QTLs related to the stay green character Staygreen consensus QTL of B35

LgB LgC LgD LgG LgH LgILgA LgE LgF LgJ

Linkage drag (dwarfing genesGrain setting and quality)Stg2

Stg1

StgB

Stg3

StgA

Stg4

Stg2LgC

Xtxp231

Xtxp59

Xtxp31

Xtxp120

R locus (pericarppigmentation)

Z locus (mesocarpthickness)

Need to further saturate the staygreen QTL genome portion

MAS for sorghum

Evaluation in large 2.0m PVC cylinders under drought

05

1015202530

30-60

cm90

-120 c

m15

0-180

cm21

0-240

cm27

0-300

cm

% o

f roo

t in

shal

low

laye

r

R16DoradoB35E36-1

Staygreen

Roots are involved in staygreen QTL(s)

Chickpea - RootsBefore

Chickpea - Roots

Screening of the minicore collection for root depth

Dep

th (c

m)

140

020406080

100120

160

Screening procedure easier (1.2 m PVC tubes)

Chickpea - Roots

r = 0.77

RLD at 60cm depth

Seed

yie

ld

A good relation between deeper rooting and seed yield

An essential question to answer: Roots for what environment??

Chickpea - RootsICC283

0.70

0.80

0.90

1.00

1.10

234 Genotypes tested

Roo

t Dep

th (m

)

Annigeri ICC4958 ICC8261

One QTL from “old” population Annigeri x ICC4958

New RIL pops from more varied parents

About 350 SSR markers available: Need more!!

Groundnut - Transpiration efficiency

Two approaches:

RILs DREB1A transgenics


Phenotyping of RIL for transpiration efficiency (TE) in groundnut

RILs


RILs

0

1020

3040

50

2.65 2.75 2.85 2.95 3.05 3.15 3.25 3.35 3.45 3.55

Transpiration efficiency (g kg-1)

Freq

uenc

y of

RIL

s (n

umbe

r)

TAG 24

ICGV86031

Good segregation between RILs


Available SSR markers : 900

Already tested : 463

Polymorphic markers : 35

18

E7

2C

11

20

12

13

E0

9

T I T I T I T I

Segregation data on ABI (9 markers)

T= TAG24, I= ICGV 86031AA

A

B

B

B

A clear need todevelop more markers

Develop syntheticgroundnut from wildancestors

RILs


Testing TransgenicsTesting Transgenics

P2 Glasshouses

DREB1A


DREB constructs used for DREB constructs used for AgrobacteriumAgrobacterium--mediated transformation

DREB1Amediated transformation

Groundnut Variety Used: JL 24• Total no. of transgenic events: 30• Generation: T3 to T5

Groundnut - Transpiration efficiencyGroundnut Dry-Down set-up

DREB1A


Wild type JL24DREB1A

Dendrogram based on soil moisture value where Trdeclines and number of days to deplete soil water

RD19

RD12

RD20

RD2RD11


TE under well watered and drought stressin 5 DREB1A events and JL24

DREB1A

JL 24RD 19RD 12RD 20RD 2RD 11

2.054.315.133.194.094.96

TE - WW TE - DS

4.294.994.634.526.125.59

Most DREB1A have larger TE than JL24 under WWTwo events with higher TE under both water regimes


Range of values in TE in a RIL population and in DREB1A groundnut

DREB1A

01234567

RIL DREB WellWatered

DREB drought

TE (g

DW

/kg

wat

er)

Min

Max

Larger range of variation for TE in DREB1A

Conclusion

MAS (pearl millet and sorghum)Need to saturate QTL areas to increase the efficiencyPyramid with other QTLsGet rid of linkge drag

Root-Chickpea: More markers, QTL identification, Start marker-assisted breeding

TE-Groundnut: More markersRe-synthesize the cultigen from its ancestorsTransgenic approachNew traits

Thank you

molecular breeding & genetic engineering for drought ...super7/30011-31001/30321.pdf · mas...

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