Sukhwinder SinghWheat-Lead, Seeds of Discovery (SeeD)

(suk.singh@cgiar.org)

 

International Maize and Wheat Improvement Center (CIMMYT), Apdo. Postal 6-641, 06600, Mexico DF, Mexico

IWC- Sept., 22, 2015

Gene Bank Biodiversity for Wheat Prebreeding

Posters # P083 & P085

seedsofdiscovery.org/wheat/

1. Pre-green revolution era

2. Green revolution era

?3. Climate change era

Why Use Gene Bank Biodiversity?

Next generation variety = Climate resilience + Yield + Input efficient

Genetic resourcesGenomics

Trait focus

Bottlenecks in conventional breeding

Improve efficiency Enhance precision

Mobilize gene bank for novel variation Exploit

• Transgressive segregation• Recombination

An Inclusive Approach at CIMMYT: SeeD-Wheat

Stress tolerance Quality

Genetic Resources

+Genomics tools= Pre breeding

Synergistic approach: Capture value of germplasm resources through genomics

8000 Mexican landraces

Phenotype(Heat, Drought, Quality)

GBS profiling(20K SNPs)

(A) Diversity analysis (B) Core set development

(C) Core set evaluation(D) Trait donor identification(E) Pre-breedingHeat, Drought

Diseases, Quality

Michoacán: Rare allele hot spot

Gene Bank to Breeding Pipeline

Large-scale efforts to move useful gene bank diversity to breeding pipelines

Diversity profiles

Global wheat diversity in

process

GBS map

28K wheat GBS map

Trait donors

Donors for heat, drought, diseases & quality

Characterization

Large-scale germplasm

characterization

Core sets

Core set of wheat landraces

Novel alleles

New alleles for adaptive traits

LTP resource

Large scale prebreeding for impact delivery

GWAS

GWAS for heat, drought, diseases & quality

CIMMYT SeeD-Wheat: Genetic and Genomic Resources

Genomics of Gene Bank Accessions

Value of a gene bank resides in rare allelic variations and captured by high density genome sequencing

Rare allele variation in Mexican wheat landraces

Mexican landraces with grain yield advantge upto 250 g m-2 under heat stress (Cd. Obregón, México)

0

20

40

60

80

100

120

140

Early floweringLate floweringMedium flowering

Grain yield (g m-2)

Num

ber o

f acc

essi

ons

150 200 250 300 350 400 450

Control: Elite bread wheat (Sokoll), 186 g m-2

Exploring Gene Bank for Heat Tolerance

• Tolerant Mexican landraces (YELLOW)

• Tolerant Iranian landraces (RED)• Elite lines (BLUE & GREEN)

PCA

Association mapping for yellow rust in wheat landrace

Accession / Pedigree Yr (%) in Mexico Yr (%) in India

CHIH95.5.18 20 10

CHIH95.5.23 10 10

DGO95.3.8 20 10

OAX93.1.1.1 20 5

Susceptible check 100 100

Yellow rust resistant wheat landraces

Screening Gene Bank for Yellow Rust

Screening Gene Bank for Biofortification

Nu

mb

er o

f gen

otyp

es

Grain Zn concentration (ppm)

Evaluation for Zn content

GWAS for Zn content

8,000 advanced lines selected under heat, drought, and for plant type

Product ready for multi-location evaluation

Genetic populations to accelerate gene discovery

1000 Linked top cross populations Outcomes:

Wheat Prebreeding at CIMMYT

CIMMYT• Mexican landraces• Primary synthetics• Historical breeding

lines from CIMMYT

FIGSLandraces from:Iran, Iraq, Afghanistan, Pakistan, and IndiaICARDA

FIGS material screened at ICARDA for heat and drought tolerance

Prebreeding Populations: Exotics and Elites

AUSTRALIACollections from different parts of the world, adapted to hot environments of Australia

Elites: CIMMYT’s best 25 elite genotypesFIGS: Focus Identification Germplasm Strategy

General genetic diversity Functional diversity

Elites

Exotics (FIGS, Australian hot, primary synthetics)

Diversity Profiles of Gene Bank Accessions

Outcome: Panel of exotics crossed with multiple elites for developing bridging germplasm

Prebreeding Product for Breeding Pipelines

8K prebreeding lines selected after screening for heat, drought, input efficient and plant type

4,000 Topcross-derived fixed lines

Select 40% of the lines

Genotype and phenotype the training set, develop GS model

Apply GS model to lines

Remaining lines

Select lines with high GEBV and intercross

Make F2 and F3 populations

Identify lines with positive allelesValidate and advance

Product delivery in three years

LTPs: Resource for Genomics-assisted Breeding

Wheat Prebreeding: Path to Deliveryx

Segregating population

Screening in target environments - Mexico, South Asia, Africa

Introgress into breeding germplasm to develop varieties

CIM

MYT

NAR

S

El Batan Diseases, input useRusts, plant typeTolucaH, D, YieldObregon

Selection

FARMERS

Exoticssynthetics, landraces, FIGS

Elite

Cultivar developmentAt CIMMYT and

elsewhere

IWYP, HEDWIC

Yield potential; heat/drought

tolerance

DRRW, Harvest+

Rust, nutritional

quality

Genebanks

Geneti

c div

ers

ity

SeeDSystematically

mobilizing new Diversity

Partnerships with trait-specific projects: Population development

for genetic analysis and pre-breeding

Partnerships with genebanks: Germplasm characterization

SeeD-Wheat Synergies

Country-specific projects (WISP, BREADWHEAT)

Strategic researchGenomics, Phenomics

Summary and Path Forward Wide variation identified for agronomic and quality traits, as well

as disease resistance

More than 1,000 exotic accessions subjected to prebreeding

8,000 advanced germplasm lines ready for use in breeding pipelines

Trait donors identified and shared with the breeders for introgression into elite germplasm

GBS characterization of 50,000 +25,000 (CIMMYT+ICARDA gene banks) accessions completed and ready to be placed in public domain

Core collections of landraces available

Potential linkage being developed with NARS to deliver impact at farmers’ fields

We acknowledge CIMMYT researchers and collaborators for their contributions