Wheat Disease Assessment Prairie Grain Development

Committee Brent McCallum AAFC Morden MB

Chair of the Disease Evaluation Team, Wheat Rye and Triticale Sub-committee of the PGDC

Prairie Recommending Committee for Wheat, Rye and Triticale

Candidate Lines are Evaluated for Disease Resistance, End Use Quality and Agronomic

Performance by;

• Disease Evaluation Team.

• Quality Evaluation Team.

• Agronomy Evaluation Team.

Evaluation Process

• Each evaluation team defines the criteria which constitute merit for each area.

• For disease the common diseases in western Canada are considered.

Disease Evaluation Disease Priority

Stripe rust Leaf Rust Stem Rust Common Bunt

Fusarium Head Blight

Leaf Spotting Diseases

Loose smut

1 (2017) 1 1 1 1 2 (formerly 1)

2 (formerly 1)

Priority 1 = Those diseases for which Coop testing is being done and the "Do-Not-Object-To" level of resistance is necessary for support for registration. Priority 2 = Those diseases for which breeding and pathology research is being done in western Canada and a minimal level of resistance is desirable to reduce economic loss to producers. A five point rating system of R, MR, I, MS and S is used to describe Priority 1 disease ratings where R= Resistant, S= Susceptible, M= Moderate, and I= Intermediate.

Are We Testing the Right Diseases?

• Fusarium head blight is a major disease across the prairies (30% of all wheat deliveries downgraded due to FHB in 2014).

• Leaf and stem rust are common in eastern prairies.

• Bunt and stripe rust common in the western prairies.

• Leaf spotting diseases – are common and important, but less emphasis is placed on these in breeding programs (complex of causal species).

• Ergot? Testing would be difficult.

Leaf Spotting Diseases

• There are at least four different species that cause leaf spotting diseases in wheat (Tan spot – Pyrenophora tritici-repentis, Stagnospora blotch Phaeosphaeria nodorum, Septoria blotch Septoria tritici, and Spot blotch Bipolaris sorokiniana).

• Resistance to each is likely genetically different.

• High levels of leaf spot resistance will require resistance to each of these causal species.

The “Do-not-object” guidelines for Priority 1 diseases wheat and triticale in Western Canada.

Disease CWRS CPS GP CWHW CWAD SWS CWRW Triticale Spelt

Leaf Rust I I I I I MS

(I 2017) I I I

Stem Rust I I I I I MS

(I 2017) I I na

Common

Bunt I I I I I

MS

(I 2017) I I I

FHB I I I I MS MS MS MS MS

Stripe Rust I (2017) I (2017) I (2017) I (2017) I (2017) I (2017) I (2017) I (2017) I (2017)

. Disease Checks and Acceptable Disease Severity Levels for Priority 1 Diseases

Rating Stem Rust

Check

Stem Rust Sev. (%)

Leaf Rust

Check

Leaf Rust

Sev. (%)

Stripe Rust

Check

Stripe Rust

Sev. (%)

FHB

Check

FHB Index (%)

Bunt

Check

Bunt

Sev. (%)

R Glenn 1-10 Lillian 0-5 FHB37 1-25 McKenzie 1.8-4.6

MR McKenzie 10-20 AC

Andrew 10-20 5602HR 12-35 4.0-18.6

I Columbus 20-40 Glenlea 10-40 CDC

Imagine 35-45 AC Cora 12-42 Neepawa

13.7-25.6

MS AC Barrie 50-80 Laura 50-60 18.8-46.4

S Hoffman 80-100

Thatcher 80-100 AC Barrie 80-100 CDC Teal*

64-100 Laura 34.5-58.4

Public Coop Disease Coordinators

• FHB – Maria Antonia Henriquez (Morden - AAFC) and Anita Brule-Babel (Carman – U of M).

• Leaf Rust – Brent McCallum (Morden – AAFC).

• Stem Rust – Tom Fetch (Brandon – AAFC).

• Stripe Rust – Harpinder Randhawa (Lethbridge – AAFC).

• Common Bunt – Therese Despin (Lethbridge – AAFC).

Assigning Disease Ratings from Disease Data

• For each disease lines are inoculated with the races/isolates appropriate for western Canada.

• They are grown in disease nurseries (often irrigated to promote disease) then rated for the severity of the disease.

• These ratings are compared to the checks and the overall average of the nursery to develop a rating scale (R,MR, I, MS, S).

• For leaf rust the scale commonly used is 0-10%=R, 11-30%=MR, 31-39%=I, 40-60%=MS, and >60%=S. This varies by disease and year of testing, depending on the overall severity of the nursery.

• For Rust Rating a Modified Cobb Scale is used described by;

• Peterson, R. F., Campbell, A. B. and Hannah, A. E. 1948. A diagrammatic scale for estimating rust intensity on leaves and stems of cereals. Can J Res 26.:496-500.

FHB Visual Index Rating

FHB FHB FHB FHB FHB FHB FHB FHB FHB FHB

Stem Leaf Mor Mor Mor Mor Mor Car Car Car Car Car

Rust Rust Bunt VRI ISD VRI ISD

Entry Sev. Rate Sev. Rate mean Rate VRI Rate DON ISD Rate VRI Rate DON ISD Rate

2014 PT 472 1 R 0 R 7.8 MR 63.0 S 59.1 39 I 43.7 MS 13.5 10.8 MS

2013 PT 472 15 MR 1 R 19.3 I 40.7 S 53.5 MS

2012 PT472 2 r 12 MR 22.8 I 13 I 6.6 19 I 36 I 48

Overall PT472 R R I S

2014 PT 474 10 MR 0 R 12.5 I 48 I 36.3 24.6 R 32.6 MS 9.2 8.0 I

2013 PT 474 25 MR 0 R 17.5 MR 30.0 MS 38.8 I

2012 PT474 5 r 5 R 7.25 R 21.0 S 5.4 22 I 46.8 MS 63

Overall PT474 MR R I MS

2014 PT 588 1 R 38 I 26.3 MS 45 I 56.8 37 MR 21 I 10.5 8.4 I

2013 PT 588 5 R 27 MR 3.3 R 15.3 I 9 MR

2012 PT588 5 mr 18 MR 12.8 MR 9 MR 5.9 16 I 37.5 I 27

Overall PT 588 R MR MS I

2014 PT 642 1 R 0 R 31.3 S 38.2 I 39.5 26 MR 25.5 I 17.0 12.5 MS

2013 PT 642 7 R 0 R 11 MR 12.3 MR 23.9 MR 23.0

2012 PT642 2 r 5 R 22.5 I 16 I 4.7 21 I 21 MR 30

Overall PT 642 R R S I

Stripe Leaf Stem Common Loose Leaf

Candidate line 2015

rust rust rust bunt Smut FHB Spots Disease Agronomy Quality WRT

BW496 MR R MR S MS I MS Object Support Do not object

Support

BW499 MR MR MR I MS MR MS Support Support Object Object

BW963 R R R MR I MS I Do not object

Support Object Support

BW965 R MR R MR S I I Support Support Do not object

Support

BW966 R R R I R I MS Support Support Do not object

Support

BW968 R R I MS MS I I Do not object

Support Object Object

BW971 MR MS R MS MR I I Object Support Do not object

Support

DT577 R R MR I MS MS MS Support Support Do not object

Support

DT578 MR R MR R I MS I Support Support Support Support

DT579 R R MR R I MS MS Support Support Do not object

Support

Variety Descriptions

MB Seed Guide Site Fusarium

2016 (Draft) Years Yield Loose Common Leaf Stem Leaf Stripe Head

Class/Variety Tested bu/acre Smut Bunt Spots Rust Rust Rust Blight

5602HR 90 64 R MR I R R I MR

5603HR 41 63 MS I MR MR R MS I

5604HR CL 40 62 MS I MS R R - I

5605HR CL 31 62 R MR MS MS R MR MR

AAC Bailey 28 50 MS MR I R R - I

AAC Brandon 42 65 MR S I R R MR MR

AAC Cameron VB 20 69 S R I MR MR S I

AAC Connery 17 57 MR I I R MR R MR

AAC Elie 42 64 I I I R R MR I

AAC Jatharia VB 20 69 S MS I I R I I

AAC Prevail VB 31 61 S S MS MR R R I

Prairie Seed Guides Use the PGDC Ratings

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015

Dis

eas

e R

atin

g S

= 1

, MS

= 2

, I =

3, M

R =

4, R

= 5

Average Disease Resistance in Bread Wheat Candidate Lines DET-WRT

Leaf Rust

Stem Rust

Common Bunt

FHB

Prairie Seed Guides Use the PGDC Ratings

• Each of the prairie seed guides (MB, SK and AB) have now switched to the PGDC scale (R, MR, I, MS, S) from the previous scale (VG, G, F, P, VP).

• Ratings can be changed if additional data is generated post-registration. Needs to have a high level of disease, include checks, and be replicated.

• MCVET and AAFC collaboratively test varieties post-registration for FHB, DON accumulation and leaf rust.

Wheat Disease Assessment

• The system is time and labour intensive.

• Helps to ensure that candidate cultivars are screened thoroughly for disease resistance.

• Provides reliable, multi-year, replicated data for the Prairie seed guides.

• Pressure to reduce the years of testing, and diseases tested, to register cultivars faster.