Feed the Future Innovation lab: Improved Wheat for Heat Tolerance and Climate Resilience

Feed the Future Innovation lab: Improved Wheat for Heat

Tolerance and Climate Resilience

Kulvinder S. Gill

Washington State University

Project partners • Washington State CCSU, Meerut

• DWR, Karnal GBPU, Pantnagar

• Kansas State JK Seeds

• Metahelix NBPGR

• Dupont-Pioneer PAU, Ludhiana

• RAU, Pusa IARI, Delhi & Wellington

Project Goal Develop high-yielding, heat-tolerant wheat cultivars for the Indo-Gangatic Plains

Specific Objectives 1. Develop heat tolerant varieties using marker assisted background

selection and forward breeding approaches: Acurate phenotyping, QTLs, enzymatic markers, fast breeding methods

2. User-friendly markers for heat tolerance: QTLs, physiological markers, biochemical markers

3. Pyramid genes with complementary mechanisms of heat tolerance: Doubled-haploid approach, Objective 4 critical for this objective

4. Understand physiological mechanisms of heat tolerance: Study genetic, physiological, biochemical, and epigenetic mechanisms controlling heat tolerance

5. Scientist training and exchange: Exchange and collaboration (senior scientists), training (younger scientists), and PhD student training.. Younger scientists are a major focus of the project.

Genetics Genomics physiology molecular biology Scaling up

Fast breeding

Adoption

Discovery

Products

Products

SCALING UP AND LINKAGES WITH OTHER INNOVATION LABS

• Heat Screening Methods • Heat tolerant germplasm • Heat tolerant varieties • Markers/Enzymatic assays/other screening tools • Relationship between heat and drought tolerance • Effect of terminal heat on grain quality • Novel breeding and genotyping approaches • Heat tolerance vs disease severity • Others?

Breeding strategy to develop heat tolerant varieties

1. Evaluate cultivated wheat germplasm to select 10 donor lines

2. Select a recurrent parent with highest yield potential and wide adaptation

3. Simultaneous detection and utilization of QTL

4. Forward breeding to increase yield over the recurrent parent

5. Gene pyramiding to combine genes with complementary gene action

Donor Selection • Select known heat tolerant material from

around the world: Selected 75 lines

• Evaluate by multi-location field, as well as controlled condition screening for heat tolerance

• Enzyme thermal stability tests on the donor and recurrent parents

• Select 10 most heat tolerant lines with complementary heat tolerance mechanisms

MABS&MAFB: Simultaneous detection and use of QTLs

Recurrent parent X Donor F1 BC1 and BC2 DH mapping population MABS QTL analysis

A B D A B D

Marker-Assisted Background Selection

BC2F3 Field Selection based Backcross Breeding

BC4F7

Graphical Genotypes

97% RPG 80.5% RPG

Recurrent Parent Donor Parent Randhawa et al. 2009, PLoS ONE 4 (6): 5752

Commonly used physiological Traits

• Canopy Temperature Depression (CTD) • Stomatal conductance • Grain filling duration (GFD) • Membrane thermo-stability (MT) • Chlorophyll content and fluorescence • Stem reserve mobilization

Reliability and reproducibility issues

Heat tolerance mechanisms in wheat

Photosynthesis

Sugar Starch

Sugar transport

Proposed Approach for Physiological studies Hypothesis: At least three different mechanisms for

heat tolerance:

1. Maintaining photosynthesis at higher a temperature

2. Maintain transport of sugars to the developing grains

3. Maintain conversion of sugars into starch

These mechanisms are expected to be controlled be different sets of genes thus should be

complementary.

Variation for Root length in the AM population

Coleoptiles length vs. seedling emergence

Effect of temperature on germination

PBW343

Indian

KSG33

KSG63

KSG89

KSG126

KSG233

Germ

inat

ion

Perc

ent

age

Effect of temperature on coleoptiles length

PBW343

Indian

KSG33

KSG63

KSG89

KSG126

KSG233

Col

eopt

iles

leng

th

Results summary of initial screening of heat tolerance donors

BLUE – HIGHLY Susceptible, no seed set RED - Susceptible, 0.1 to 0.49 GREEN – Tolerant, 0.67 to 0.88

Results summary of initial screening of heat tolerance donors

DARD BLUE – HIGHLY Susceptible, no seed set ORANGE- Susceptible, 0.1 to 0.49 LIGHT BLUE– Tolerant, 0.67 to 0.88

Spike Weight

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

16.00

18.00

20.00

GEMIZA10 GIZA 168 RED FIFE Seri 82 SONORA 64

cont mean

Treat mean

CONTROL

TREATMENT

KSG121 KSG168 KSG311 KSG82 KSG64

Our approach • Check thermal stability of various enzymes in

involved in photosynthesis, sugar transport and grain filling

• Screen for RO and others correlating with heat tolerance at flowering

• Screen the donors to identify enzymes or other physiological parameters corresponding to each donor line

• Develop high-throughput assay and use as marker for MABS and forward breeding

Genetics Genomics physiology molecular biology Scaling up

Fast breeding

Adoption

Discovery

Products

Products