Targeting traits associated with the drought stress response to breed grain crops with increased water use efficiency and

productivity for SC growers

Florence, SC — Image taken on 2 July 2019

Most common water stress phenomenon for grain crops in SC:

Pre-flowering combined heat and drought stress during early reproductive growth

Leaf rolling BlastingSusceptible pre-flowering

window

Model: Grain sorghum

r = 0.36 r = 0.21

Blasting ~ Yield: r = -0.16Rolling ~ Yield: r = -0.07

Sorghum

Association Panel

400 inbred lines

Select

Advanced

Subset

50 genotypes

Hybrid

Diversity Panel

300 hybrids

32 parents

Top 5%

20 inbreds; 15 hybrids

Bottom 2%

8 inbreds; 6 hybrids

1 reference genome

Greenhouse

Validation

50 genotypes

Advanced

Field Testing

Top 15 hybrids

Genome-wide

Association Mapping

Genetic markers

Genetics of

Hybrid Vigor

GEBVs; PopVar

Flowchart of objectives and deliverables

Year 1 Field EvaluationReplicated RCBD

Florence, SC — Image taken on 24 July 2019

0.000

0.050

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0.250

6/12/1

9

6/19/1

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6/26/1

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7/3/1

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7/10/1

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7/17/1

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7/24/1

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7/31/1

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8/7/1

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8/14/1

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8/21/1

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8/28/1

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9/4/1

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9/11/1

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9/18/1

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9/25/1

9

Volumetric Water Content (water:soil ratio)

VWC_6in

VWC_15in

VWC_24in

Wat

er:S

oil

rati

o

Hurricane Dorian (2.5” rainfall)

7/22: 2nd WUE collection date

7/2: 1st WUE collection date

Harvest window

Table 1. Fifty selections for the advanced subset for additional testing of WUE traits in year 2.

Category GenotypeAnthesis

days

Heightcm

Leaf Rolling0-9 scale

Senescence0-9 scale

Ref Genome BTx623 73.8 125.3 2 1.5

SAP-high WUE Msumbji SB 117 69.0 126.2 2 1.5

SAP-high WUE Bulfontein White Kafir Corn 65.3 117.2 2 1

SAP-high WUE Lambas 70.3 114.5 2 1.5

SAP-high WUE SC 1019 82.5 124.7 2 1

SAP-high WUE SO 16 66.2 119.0 1.5 1.5

SAP-high WUE KA 21 Gajerar Kaura 75.3 106.2 1.5 1

SAP-high WUE Budy 77.1 123.0 1.5 1

SAP-high WUE Tx2911 77.0 111.5 1.5 2

SAP-high WUE QL3(India) 80.9 119.7 1.5 1

SAP-high WUE No. 5 Gambela 76.7 86.2 1 3

SAP-high WUE No. 35 Mab 75.2 115.8 1 2.5

SAP-high WUE KA 24 67.7 133.8 1 2

SAP-high WUE MACIA 76.2 142.2 1 1

SAP-high WUE SAP-168 67.3 111.8 1 2

SAP-high WUE KS 115 66.9 112.7 1 1.5

SAP-high WUE SRN39 81.3 144.9 1 1

SAP-high WUE Dorado 82.8 137.7 1 4.5

SAP-high WUE Pinolero 1 79.4 137.3 1 3

SAP-high WUE QL3-TEXAS 66.9 115.3 1 1

SAP-high WUE COMBINE HEGARI 71.4 113.4 1 2

SAP-high WUE Segaolane 64.0 168.0 1.5 1

SAP-low WUE No. 64 Netch Addesho 90.3 91.8 9 2.5

SAP-low WUE SAP-150 71.5 106.3 7.5 3

SAP-low WUE BTx642 78.6 99.8 7 1.5

SAP-low WUE SC 1047 89.8 120.5 7 3.5

SAP-low WUE Kokla 69.1 96.0 6.5 2.5

SAP-low WUE 80M 80.8 110.0 6.5 4.5

SAP-low WUE No. 59 Bekedjie, Kembolcha 73.0 93.3 9 3

SAP-low WUE 2033Z-3 76.0 92.3 8 4

HDP-highWUE ATx2928/P89010 68.0 175.5 6.0 1.0

HDP-highWUE ATx642/94Q63 71.5 292.5 5.5 2.5

HDP-highWUE ATx2928//(WWR/R4B1) 74.0 149.0 5.5 1.0

HDP-highWUE ATx2928/54.K.94(WWR) 69.5 196.5 5.5 1.0

HDP-highWUE ATx642/X13-17-1-7-4 69.5 130.5 5.0 1.0

HDP-highWUE ATx2928//(NYT/R380) 66.0 139.0 5.0 1.0

HDP-highWUE ATx2928/KA 21 Gajerar Kaura 74.0 158.0 5.0 1.0

HDP-highWUE ATx2928/CE151-262-A1 68.0 174.5 5.0 1.0

HDP-highWUE ATx642//(WHTLD/ECG30) 69.0 155.5 4.5 1.0

HDP-highWUE ATx2928/Feterita Gondal 57.5 95.0 4.5 1.0

HDP-highWUE ATx2928/Mashila 69.0 120.0 4.0 1.0

HDP-highWUE ATx2928/SC 748-5 65.5 161.5 4.0 1.0

HDP-highWUE ATx2928/Karad 2-7-11 68.0 125.5 3.5 1.0

HDP-highWUE ATx2928/KA 24 66.0 165.5 3.0 1.0

HDP-highWUE ATx2928/WHITE KAFIR 56.0 193.0 2.0 1.0

HDP-low WUE ATx642/SC 49 61.0 224.0 9.0 2.5

HDP-low WUE ATx642//(P89/R3117) 74.0 129.5 9.0 1.5

HDP-low WUE ATx2928//(AUS_B112/PHB82) 68.0 128.5 9.0 1.5

HDP-low WUE ATx642/SC 1416 73.0 165.0 9.0 1.5

HDP-low WUE ATx642/SC 1215 63.5 144.5 9.0 1.5

HDP-low WUE ATx642/PH 232 71.5 120.0 9.0 1.0

Advanced Subset

Evaluation

Greenhouse testing:• Leaf rolling• Foliar senescence• Pollen volume• Fertilization efficiency• Yield components

Field validation:• Yield trial for subset of 21 hybrids

• Dryland vs. irrigated (sandy soils)• Three reps per condition

Objective: Identify physiological mechanisms

Objective: Validate Year 1 and GH results

Optimizing root architecture to capture water in sandy soils

What is (if it exists) the optimal root system architecture for grain crops in this environment?

Collaboration to measure belowground traits

Novel RootTracker 3D sensing design predicts root architecture non-destructively in real-time

Pre-flowering drought tolerance would be a major stability trait for sorghum in the southeastern US

Florence — 12 Aug 2019

Florence — 9 Sept 2019

Collaboration to measure belowground traits

Validation of RootTracker sensing with shovelomics

Collaboration to measure belowground traits

Wheat Scab Nursery — Pee Dee REC (Florence, SC)

• Evaluate thousands of breeding lines annually for disease resistance• Mist-irrigated nursery inoculated with Fusarium graminearum

Applied studies to improve breeding efficiency