J. Scott Armstrong

Research Entomologist

USDA-ARS, Wheat, Peanut and Other Field Crops Research Unit, Stillwater, OK

Using greenbug resistant sorghum’s for cross-resistance to sugarcane aphids

Thanks to:Sugarcane Aphid Task Force:

Dr. Bill Rooney - Texas A&M Crop ScienceDr. Gary Peterson - Texas AgriLife, LubbockDr. Raul Villanueva – Texas AgriLife, Welsaco, TX Dr. Mike Brewer – Texas AgriLife, Corpus Christi, TXDr. David Kerns – LSU, Macon Ridge Research StationDr. Scott Armstrong – USDA-ARS, Stillwater, OKDr. Charles Allen - Texas AgriLife, San Angelo, TX Danielle Sekula-Ortiz - Texas AgriLife, Welsaco, TX Sorghum Checkoff – Justin WeinheimerNational Sorghum Producers – Tim Lust

Many others

SCA origin, host plants and biotypic diversity

Greenbug cross-resistance from HPR evaluationsParental lines (differentials) used in GB resistance

Commercial evaluations (varieties) for HPR

Live colonies of SCA for Biotype determinations

44 individual clonal colonies maintained on TX 7000Collected from sugarcane, grain sorghum, Johnsongrass, forage sorghum.

Florida, Louisiana, Texas, Oklahoma, Arkansas, Mississippi, …………..

Original colony from Matagorda Co. Texas (Bay City), collected by Clyde Crumley from grain sorghum used for all screening trials.

World distribution of the sugarcane aphidsSugarcane Sorghum Rice Maiz

eNot

Present

Sugarcane aphids found on different host plants in the world. Notice that this aphid only infested one plant host species in some

countries while other hosts were not affected (Adapted from Singh et al. 2004)

Host Cultivar

Forage sorghum AF7301

Johnsongrass Local (Stillwater)

Sugarcane “Weslaco”

Proso Millet from OK producer

Field Corn “B73”

Teff Grass “Tiffany”

Winter Wheat “Tam 101”

Rye “Elbon”

Barley “812”

Hosts of the Sugarcane aphid in the U. S. ?????

Host CultivarDamage Rating

(1-9) Mean number of

SCA /plant

Difference inPlant height

(cm)

Forage sorghum AF7301 8.0 ± 0.84 1150 ± 51 20.7 ± 2.97

Johnsongrass Stillwater 6.3 ± 1.29 1229 ± 95 16.4 ± 6.81 Sugarcane “Weslaco” 3.3 ± 1.39 115 ± 15 0.00

Proso Millet Local NS NS NSField Corn “B73” NS NS NSTeff Grass Tiffany NS NS NS

Winter Wheat Tam 101 NS NS NS

Rye Elbon NS NS NSBarley 812 NS NS NS

Hosts of the Sugarcane aphid in the U. S. ?????

Sorghum host plant resistance – one of the best methods of preventing damage and controlling costs. What do we have from GB resistance???

HPR = antibiosis, antixenosis, tolerance

Chlorosis Ratings 1 – 9 damage scale

Free-choice test vs no-choice test, field evaluated

Biotype “E”: TX 7000 and TX 2737 are susceptible, TX 2783 and PI 550607 are resistant

Biotype “I”: TX 7000, TX 2737 and TX 2783 are susceptible. PI 550607 is resistant;

Biotype “K”: PI 550607, TX 7000, TX 2737 and TX 2783 are all susceptible.

M 627 – Mycogen, now Dow Ag. Sci. Biotypes C, E, I and K greenbugs

PI 550610 – recently discovered to be a little better than 550607, by IRI studies.

PI 264453 – From Spain (Africa) 1960, resistant to GB C and E. Parent to many commercial lines

Colony TX TX TX PI

Selection 7000 2737 2783 550607

C S R R R

E S S R R

F S S

G S S S R

H R

I S S S R

K S S S S

Sorghum lines used to determine Greenbug differentials

SCA used were from Matagora Co, TXThanks to Clyde

Crumley, United Ag Cooperative, Inc.

Wharton TX

Crop CultivarGrain Sorghum TX 7000Grain Sorghum TX 2737Grain Sorghum TX 2783Grain Sorghum PI 550607Grain Sorghum PI 550610 <Grain Sorghum M 627 <Grain Sorghum JS222 <Grain Sorghum PI 264453 <

Forage sorghum AF7301 <Johnsongrass _ Very good

Sugarcane <Proso MilletField Corn B73Teff Grass

Winter Wheat Tam 101Rye Elbon

Barley 812

Evaluation #1 - host plants / resistance

Infested October 28, 2013 / 10 aphids per plant,

when plants were 2-3 leaves.

Evaluated 12 November, 2013 for:

Chlorosis / Damage rating (1 – 9)

Plant height, Leaf number (node number)

Tol.

AB AB

GB E res.

2014 &15 Replicated Free-choice Evaluations:

Monsanto (Dekalb), Chromatin, B&H Genetics,

Dow/Mycogen (Agrigenetics), Adavanta US

Webster et al. 2001, 0 – 9 Damage rating scale

PI 550610SC110PI 550610

2014 Field Evaluations:

Texas A & M Field NurseriesDr. Bill Rooney & Dr. Gary Peterson

Weslaco, TX seed treatedWeslaco, TX no seed treatment

Chorpus Christi, TX seed treatedChorpus Christi, TX no seed treatment

Sharma et al. 2013 1 – 9 Damage rating scale (at full maturity).

Dam

age

Rat

ing

Summary:

SCA host range is within the Sorghum (bicolor, halepense) and Saccharum officinarum genotypes.

TX 2783 from SC110 shows high tolerance, and is the basis for resistance. Antibiosis comes from PI 550610 (i.e. DKS 37-07)

Several other commercial lines from the TX 2783 background have high tolerance (Monsanto, Chromatin, Others???).

Dr’s B. Rooney, G. Peterson, L. Mbulwe, & S. Armstrong are releasing 2 parental lines Tx3408 Tx3409 for breeding for SCA resistance, this is all good news for sorghum breeding programs.

We need other sources of resistance, with combinations of all three.

B11055 B11053Dr. Bill Rooney, Texas

AgriLife, Weslaco, TX Fall 2013

Thanks to:

Nick Seiter, U of AJeff Gore, Mississippi StateBill White, USDA –ARS LousiannaKen Gravois, LSU Ag Center, St. Gabriel, LABlaine Viator, Labadieville, La.,Jim Swart, Texas AgriLife, Ballinger, TX Raul Villanueva – Texas AgriLife, Welsaco, TX Mike Brewer – Texas AgriLife, Chorpus Christie, TXDavid Kerns – LSU, Macon Ridge Research StationRick Minzenmeyer, Texas AgriLife, Ballinger, TXSamuel Nibouche, ICRA, FranceGary Peterson, Texas AgriLife, Lubbock, TX

Dr. Scott Armstrong, USDA-ARS

Dr. Rick GranthamOSU Entomology and

Plant Pathology

Sugarcane aphidSCA