Physiological specialization of Puccinia triticina on wheat in

the United States in 2010.

Jim Kolmer

Dave Long

Mark Hughes

USDA-ARS Cereal Disease Laboratory St. Paul MN

Puccinia triticina 2010 - USA

• 537 single uredinial isolates

• 40 virulence phenotypes total

• MLDS 30% (Lr9, Lr17, Lr39/41)• TDBJG 23% (Lr2a, Lr24) • TCRKG 13% (Lr2a, Lr26, Lr11, Lr18)

Virulence Phenotypes P. triticina 2010

Race Southeast

(52)

Northeast

(58)

Ohio Valley

(57)

TX-OK

(135)

KS-NE

(58)

MN-SD-ND

(149)

MCTSB 0% 16% 14% 0% 2% 0%

MFPSB 10% 0% 5% 7% 0 5%

MLDSD 39% 7% 2% 48% 21% 36%

TCRKG 23% 31% 56% 4% 0% 3%

TDBGG 0% 0% 0% 6% 9% 1%

TDBJG 14% 0% 14% 27% 38% 32%

Virulence P. triticina 2010

Gene

Southeast

(52)

Northeast

(58)

Ohio Valley

(57)

TX-OK

(135)

KS-NE

(58)

MN-SD-ND

(149)

Lr2a 42% 53% 75% 42% 78% 55%

Lr9 39% 19% 2% 50% 35% 38%

Lr16 0% 0% 0% 0% 0% 3%

Lr24 33% 16% 21% 42% 53% 54%

Lr26 39% 74% 79% 15% 9% 24%

Lr11 33% 78% 74% 7% 19% 4%

Lr17 52% 35% 26% 57% 36% 44%

Lr21 0% 0% 0% 0% 0% 8%

Lr39/41 39% 22% 2% 50% 35% 38%

P. triticina regional populations - 2010

Lr21 Virulence - 2010 Collections from MN-ND

Cultivar MLDSD TFBGG TFBJQ TFBGQ

TcLr21 2+3; ;2- 3+ 3+

Glenn 0; ; 2+n 22+n

Steele-ND 0; ; 2+3n 2

AC Cora ;2 ;2- 3+ 3+

Faller 0; ; 3+ 3+

RBO7 ;12- ; 3+ 3+

McKenzie ;1 ; 12+n ;2

Amidon ;1 ; 3+ 3+

Thatcher 3+ 3+ 3+ 3+

P. triticina SSR Groups 2010

• NA3 45% isolates

10 phenotypes• NA5 53% isolates

23 phenotypes• MLDSD- NA3• MFPSB- NA3• TDBJG - NA5• TDBGG- NA5• TCRKG- NA5

Top 10 Kansas Wheat Cvs 2011

• TAM 111- Lr17

• Fuller- Lr17,Lr39/41

• Art- Lr17+

• Postrock- Lr39/41

• Santa Fe- Lr3,Lr17

• TAM 112- Lr39/41

• Jagger - Lr17

• Armour - Lr39/41

• Overley - Lr39/41

• Blends

Whither Rust Pathology??Fungicide Effectiveness –

WLR-WStR

Headline Excellent

Quadris Excellent

Bumper Very good

Caramba Excellent

Folicur Excellent

Proline Very good

Propimax Very good

Prosaro Excellent

Tilt Very good

Quilt Excellent

Stratego Very good

Twinline Excellent

Moderate – High Rust pressure

$4-8 Wheat/bushel

$10-20 Fungicide/acre

Susceptible Wheat

Average >10% yield increase

>93% chance of economic return with fungicide application