Improving Phosphorus Efficiency in Sorghum by the Identification and Validation of Sorghum Homologs for Pup1, a Major QTL Underlying

Phosphorus Uptake in Rice (SorghumPup1)

ICRISAT - Mali Eva Weltzien, Fred Rattunde, Willmar Leiser

IRRI/JIRCAS Sigrid Heuer (IRRI) Rico Gamuyao (IRRI)

Matthias Wissuwa (JIRCAS)

GCP – GRM 2013, Lisbon - Portugal

Moi Unversity Sam Gudu

INRAN - Niger Soumana Souley

Cornell University/USDA-ARS Leon Kochian (USDA/CU) Randy T Clark (USDA/CU) Brittany Green (USDA/CU)

Jon Shaff (USDA/CU) Sharon Mitchell (IGD/CU)

Sylvia de Sousa Robert Schaffert Claudia Guimarães

Lidiane Braga (PhD S) Gabriel Corradi (PhD S)

Barbara Negri (Und) Fabiano Matos (Und)

ESALQ/USP Antonio Augusto F. Garcia

Rodrigo Gazaffi

ICRISAT - Niamey Bettina Haussmann and Tom Hash

Jurandir Magalhaes Barbara H Maciel (PhD student)

A Molecular Tool Kit for Highly Weathered Tropical Soils

Al toxicity

High P fixation

Low activity clay

Variable charge

> 70 % Kaolinate/ Fe and Al oxidesEquator

Capricorn

Low P soils Acid soils (Al tox)

NHCOOH

Cytoplasm

3

*

AltSB Pstol1

Plant Phys 156-1041

Fe - O

Citrate

PO4--

Band A

Band B

Band C

10 ppm (P)

5 ppm (P)

0 ppm (P)

10 ppm (P)

5 ppm (P)

0 ppm (P)0 - 20 cm

- Spatial models (r/c) - Environmental covariates

- Phenological covariates

Phenotyping for Phosphorus Efficiency

- Soil moisture strongly impaires P diffusion

- PAE x PUTIL

Phenotyping for Root Morphology (2D)

- Importance for PAE - Shallow roots?

PSTOL1 increases grain yield

PSTOL1 increases early root growth

Comparative Strategy to Validate Pstol1 Homologs as Genes Conferring Enhanced P acquisiton

Sorghum: association mapping US (converted) Panel

Contrasting parental lines Pstol1 - Rice

Maize: QTL mapping L22

Grain yield: low P soils

Root morphology: nutrient solution

Wide Diversity Panel

Parentoni et al. (2010) Maydica

Polymorphism Discovery for Linkage and Association Mapping

• Primer design for amplicon sequencing • SNP detection • Conversion to the Kaspar system • Genotyping in the association panel

Primer-BLAST Conserved Regions

Paralog-specific primers

Step 2: Producing F1: Ms3ms3

Step 3: Self-pollinate F1s

Step 4: Random Matting Cycle 1

Step 5: Random Matting Cycle 2

Step 1: Base population development

Step 6: - Random Matting Cycle 3 - Pup1/AltSB validation

Selection for AltSB based on allele mining with tag markers

Genotyping

Genotyping S1s to produce S2s

Phenotype S2s and relate genotypic information on AltSB/Pstol1 with the phenotype for validation

- Provides means to validate Pup1/AltSB (higher LD) - Effect estimate - Amenable to gene pyramidation - Contingency plan based on a familiar breeding scheme (high risk project) - Entry points for new material (SorghumCI) - Cultivar release, regardless

Sorghum RMPs: pyramiding AltSB and multiple Pstol1 homologs

4 cycles of random matting

Products: - Agronomic performance under low P (SAP) - Root morphology and architecture (SAP) - Root morphology QTL - Functional markers