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NCGA 5 th Annual Canola Research Conference. Canola Pathology Program. Research update 2011. Luis del Río North Dakota State University. Disease resistance:. Pre-breeding. Sources of resistance. Breeding lines. Disease management:. Epidemiology. Fungicide trials.
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NCGA 5th Annual Canola Research Conference Canola Pathology Program Research update 2011 Luis del Río North Dakota State University
Disease resistance: • Pre-breeding • Sources of resistance • Breeding lines Disease management: • Epidemiology • Fungicide trials
Pre-breeding - SSR • PI458939 x Ames 26628 • 230 F2 plants inoculated using PIT in greenhouse • 69 F2 plants survived • F6 generation produced • Increasing seeds
Pre-breeding - SSR PI458939 x Ames 26628 Mortality (%) Generations
Identifying sources of resistance - SSR • USDA collection of Brassica napus • 300 lines evaluated for reaction to S. sclerotiorum using PIT • DNA samples extracted for association mapping • analysis • 3200 DArT markers used on population. • Data is being analyzed
Evaluation of breeding lines - SSR • 46 NDSU breeding lines with herbicide tolerance • Lab-produced ascospores and natural inoculum • Replicated trial • Incidence, severity, and yield
Evaluation of breeding lines - SSR Sclerotinia stem rot incidence and severity in field trial. Langdon, 2011 Commercial controls Breeding lines SSR severity l.s.d. (P=0.05) for incidence = 12% Incidence (%) Severity (1-5)
Evaluation of breeding lines - SSR Langdon, 2011 Commercial controls Breeding lines Most resistant lines Yield (lb/A)
Evaluation of breeding lines - SSR Reaction of elite canola breeding lines to Sclerotinia stem rot in field conditions. Langdon, 2011 Lines Incidence (%) Severity (1-5) 2009 2010 2009 2010 2011 2011 11 4 - 11 15 10 0.3 0.1 - 0.3 0.4 0.2 9092 9023 9200 Check 1 Check 2 Trial mean 12 82 14 22 30 33 0.3 3.4 0.4 0.8 1.3 1.3 3 12 6 14 16 16 0.3 0.4 0.2 0.4 0.6 1.6
Identifying sources of resistance – Blackleg 0 3 Delwiche Blackleg scale cotyledon test 7 9 Pictures courtesy of S. Markell
Identifying sources of resistance – Blackleg Reaction of B. juncea accessions to inoculations with L. maculans at cotyledon stage. 1Phenotypic reaction: R = Resistance (0-2); I = Intermediate resistance (3-6); and S = Susceptible (7-9)
Identifying sources of resistance – Blackleg Materials that exhibited resistant reaction to different pathogenicity groups of L. maculans Pathogenicity groups Plant introductions 2 3 4 T 181057 426356 426384 459007 478332 633106 - R - - R R R R R R R R R - R R - - R R - R R R
Evaluation of breeding lines – Blackleg Langdon, 2011 Commercial controls Breeding lines Severity l.s.d. (P=0.05) for incidence = 24% Severity (1-5) Incidence (%)
Evaluation of breeding lines - Blackleg Langdon, 2011 Commercial controls Breeding lines Most resistant lines Yield (lb/A)
Evaluation of breeding lines – Blackleg Reaction of canola breeding lines to blackleg in field conditions. Langdon, 2011 Lines Incidence (%) Severity (1-5) 2009 2010 2009 2010 2011 2011 28 27 30 25 32 33 32 1.7 2.8 2.4 1.7 1.6 2.1 2.0 4082 9023 9224 9067 Check1 Check 2 Trial mean 31 95 - 77 70 93 72 2.0 1.6 - 1.2 0.8 0.9 1.0 29 36 41 44 49 53 55 0.5 1.0 1.3 1.3 1.0 2.0 1.8
Disease resistance – Summary • Sclerotinia stem rot: • SSR-resistant B. napus population developed • Association mapping on B. napusPI collection in • progress • Best NDSU breeding lines identified • Blackleg: • B. junceaaccessions with resistance to PG2, PG-3, PG4, • and PG-T identified • Best NDSU breeding linesidentified
Disease Management • Epidemiology • Association between flea beetle and blackleg • Prevalence of blackleg pathogenicity groups • Fungicide trials • SSR- biologically-based fungicides • SSR- chemical fungicides • Chemical control of blackleg
Association between flea beetles and blackleg • Field trial in Langdon using cages • - Ten treatments, six replications • - Cages 20 x 5 ft • - Inoculated with spores or not • - 0 to 1,000 beetles per cage • - Cages lifted after 6th leaf stage • - Incidence and severity • measured before swath
Association between flea beetles and blackleg • GHSE trials • - Inoculated with spores or not • - Beetles allowed to feed before and after • inoculation • - Incidence and severity at flowering • - Three replications, trials repeated six • times
Association between flea beetles and blackleg Spores alone Flea beetle + spores
Association between flea beetles and blackleg Incidence (%) • Effect of flea beetle on blackleg still not clear and may • depend on inoculum concentration
Prevalence of blackleg pathogenicity groups • Isolates collected from leaves from 54 fields • from seven ND counties between 2007 and 2008 • Virulence profiles based on reaction on three • differentials: Westar, Glacier, and Quinta
Prevalence of blackleg pathogenicity groups • Eleven different PGs were detected affecting • canola foliage • PG-1 is most prevalent pathotype on leaves • although it can’t cause severe stem cankers • Ability to cause stem cankers not determined on newer PGs
SSR – Biologically-based fungicides • Polyversum (P. oligandrum) 1.5 and 3 oz, 30BF and/or at F • Serenade (2-3 qt at F) • Endura (6 oz) and Quash (2 oz) as controls a ab ab abc abc abc abc bcd bcd cd cd d SSR incidence (%) Severity (1-5)
SSR – Biologically-based fungicides • Endura, Polyversum (1.5 oz 30BF), Quash + Polyversum a ab abc abc abcd abcd cd bcd cd cd d d Yield (lb/A)
a b SSR – Chemical fungicides • Langdon, 2011 • Factorial study (18 trt) Fungicide Doses Time of application Topsin (T) Endura (E) Proline (P) Quash (Q) Switch (S) Omega (O) Tank mixes 20 fl oz 6 oz 5 fl oz 3 oz 6 oz 13.5 floz 50-50 F & F+7 F F F F F F
SSR – Chemical fungicides • Intermediate level of disease pressure • Double applications (T+T, T+E, T+P) better a a a ab ab ab ab ab abc abc abcd abcd abcd abcd abcd SSR incidence (%) Severity (1-5) bcd d cd
SSR – Chemical fungicides • Higher yields with (T+E)*2, (T+P)*2, and E a a a ab ab abc abcd abcd abcde bcde bcde bcde cde cde cde cde cde Yield (lb/A) cde
SSR – Chemical fungicides SSR incidence and severity (average 2008-2011) Percentage from control Fungicides
SSR – Chemical fungicides Yield (average 2008-2011) Percentage from control Fungicides
Blackleg –fungicide trials • Greenhouse seed treatment study: • Two experimental compounds on Westar • Seedlings inoculated at cotyledon stage • Replicated trial repeated three times • Disease incidence and severity at flowering • Foliar fungicide application in field: • Langdon commercial fields • Collaborators did not get to plant
Disease management- Summary SSR: • Biological fungicides have potential • Tank mixing fungicides help reduce cost and • provide similar levels of control • Mixes combine fungicides from different FRAC • groups to reduce selection pressure on pathogen Blackleg: • Seed treatment not effective • Foliar fungicide alone or in combination with • seed treatments in greenhouse
Acknowledgements • Canola Research Team: Achala Nepal Dante Marino • PragyanBurlakoti Shanna Mazurek • Susan Ruud • DimuthuWijeyaratneAbhishek Kumar • Mr. Curt Doetkott • Dr. MukhlesurRahman • Mr. Scott Halley, Langdon REC • Dr. Michael Wunsch Carrington REC • Dr. Brian Jenks, North Central REC • USDA-ARS/Sclerotinia Initiative • North Dakota Canola Growers Association