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Luis del Río North Dakota State University

Canola Pathology Program. Research update 2008. Luis del Río North Dakota State University. Breeding efforts. Sclerotinia stem rot Germplasm collection Breeding lines Double haploid lines. Blackleg Germplasm collection Breeding lines. Epidemiology. Sclerotinia stem rot

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Luis del Río North Dakota State University

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  1. Canola Pathology Program Research update 2008 Luis del Río North Dakota State University

  2. Breeding efforts • Sclerotinia stem rot • Germplasm collection • Breeding lines • Double haploid lines • Blackleg • Germplasm collection • Breeding lines

  3. Epidemiology • Sclerotinia stem rot • Spatial attributes of SSR epidemics • Leaf wetness and disease development • Time of inoculation and disease development • Forecasting efforts • Blackleg • Cultural practices and disease prevalence • PG and race identification

  4. Disease management • Sclerotinia stem rot • Plant population studies • Biological control products • Fungicide evaluations

  5. Breeding efforts • Sclerotinia stem rot • Germplasm collection • Breeding lines • Double haploid lines • Blackleg • Germplasm collection • Breeding lines

  6. Breeding efforts - SSR Screening the Brassica rapa collection • Three screening stages • PIT in GHSE and field • >400 accessions • AUMC used as criteria a= Hyola 357 Magnum b= Hyola 440 AUMC b* a* Accessions

  7. Breeding efforts - SSR Screening the Brassica rapa collection • No immunity observed • 42 accessions enter 2nd stage • Survivors produced S1 seed • 4 accessions to 3rd stage

  8. Breeding efforts - SSR Screening the Brassica rapa collection • 60 S1 seeds from each of four best accessions in 2nd stage • PIT at flowering • Survivors produced S2 seeds c bc ab ab ab a Mortality (%) PI 163497 Ames 21738 PI 175050 Hyola 357 Hyola 440 PI 426281

  9. Breeding efforts - SSR NDSU breeding lines • 45 NDSU breeding lines with herbicide tolerance • Field and GHSE evaluations • Ascospores used in field, PIT used in GHSE • PIT twice to prevent escapes • Mortality and AUDPC used as criteria

  10. Breeding efforts - SSR NDSU breeding lines l.s.d. (P=0.05) for mortality rate =16 Mortality (%) Breeding lines

  11. Breeding efforts - SSR NDSU breeding lines Reaction of elite canola lines to S. sclerotiorum using PIT in greenhouse conditions. Lines AUDPC Mortality (%) 427761 Pioneer 45H26 427765 330629 427709 MON-07-01 MON-07-02 1.6 1.1 1.0 1.4 1.1 1.1 1.1 48 49 59 73 73 75 75 1.2 16 l.s.d. (P=0.05)

  12. Breeding efforts - SSR NDSU breeding lines • 37 lines evaluated • Field trial in Langdon • Incidence/severity • Natural infection Commercial controls Incidence (%) Lines

  13. Breeding efforts - SSR NDSU breeding lines Reaction of elite canola lines to S. sclerotiorum under natural infection conditions. Langdon, 2008 Lines SSR incidence (%) P=0.05 0330416 30457 0427681 0427649 30522 Invigor 5550 DKL 38-25 8 a 10 a 10 a 12 ab 12 ab 45 b 35 a

  14. Breeding efforts - SSR Georgia breeding lines • 3 canola lines with excellent bklg resistance • Field trial in Langdon • Natural infection with misting b GO1114.D2 SSR incidence (%) a a a GO4023.D3 DK 30-42 G01114.D2 G04023.3 G04029.D4 GO4029.D4

  15. Breeding efforts - SSR Double haploid lines • Collaborative project with Dr. Dai (Plant Science) • Protocol to obtain DH populations via microspore culture has been developed • Haploids from PI458940 × Ames 26628 and Ames 26628 were produced. • Chromosome doubling is underway

  16. Breeding efforts - Blackleg NDSU breeding lines • 37 lines evaluated • Field trial in Langdon • Incidence/severity • Natural infection Incidence (%) Lines

  17. Breeding efforts - Blackleg NDSU breeding lines Reaction of canola breeding lines to blackleg in field conditions. Langdon, 2008 Lines Incidence (%) Severity (1-5) 0330455 0427667 30525 0330662 0427765 0330666 Westar DKL 38-25 Invigor 5550 3 3 5 8 10 10 23 30 38 0.5 2.5 5 1.5 2.0 2.5 1.8 3.2 3.2

  18. Breeding efforts - Blackleg NDSU breeding lines • 39 lines evaluated • Nursery in Manitoba • Incidence/severity • Natural infection Incidence (%) Lines

  19. Breeding efforts - Blackleg NDSU breeding lines Reaction of canola breeding lines to blackleg in field conditions (PG-2, -3, and -T). Manitoba, 2008 Lines Incidence (%) Severity (1-5) BS-113 BS-122 BS-128 BS-130 BS-132 BS-111 BS-105 BS-123 St. dev. 10 20 20 20 30 40 100 100 23 1.3 1.5 1.2 1.7 1.9 1.5 3.3 4.6 1.1

  20. Breeding efforts - Summary Materials with promising levels of resistance against S. sclerotiorum: • 4 B. rapa • 4 B. napus herbicide-tolerant lines • 2 B. napus breeding lines with resistance to blackleg Materials with promising levels of resistance against blackleg: • 2 B. napus herbicide-tolerant breeding lines (PG2) • 2 B. napus breeding lines(PG3 and PG-T)

  21. Epidemiology • Sclerotinia stem rot • Spatial attributes of SSR epidemics • Leaf wetness and disease development • Time of inoculation and disease development • Role of soil conditions on apothecia formation • Forecasting efforts • Blackleg • Cultural practices and disease prevalence • PG and race identification

  22. Epidemiology SSR spatial attributes • Characterize disease spread from a source of inoculum • Trials at Langdon and Cando in 2005-2007 SSR incidence (%) Distance (m) from source of inoculum

  23. Epidemiology Leaf wetness and disease development • Impact of interrupted wet periods on spore germination • Wet periods: 2 - 8 hours • Dry periods: 0 - 16 hours Germination (%) Dry period (hours)

  24. Epidemiology Leaf wetness and disease development • Impact of interrupted wet periods on SSR development • Wet periods: 8 - 16 hours • Dry periods: 12 – 24 hours Probability of disease development Cumulative hours of leaf wetness

  25. Epidemiology Leaf wetness and disease development • Interrupted wet periods delay but do not stop SSR development • Probability of SSR development (6 day period): • 50 hours = 5% chance • 55 hours = 10% • 60 hours = 25% • 65 hours = 60% • 70 hours = 80% • 75 hours = 95%

  26. Epidemiology Water regimes and disease development • Replicated field trial • Langdon, 2008 • Water regimes: control (rain only); daily misting; irrigation prior to flowering • Inoculation methods: naturally produced apothecia or ascospores (103spores per ml at 40% flowering) • Incidence and severity evaluated on 50 plants per plot

  27. Epidemiology Water regimes and disease development • Field trial, Langdon • 2 x 3 x 2 factorial • No difference between inoculation methods • Misted plots had significantly higher disease incidence b a a SSR incidence (%)

  28. Epidemiology Water regimes and disease development • Short cultivar had significantly higher SSR incidence • Interaction between water regime and crop height SSR incidence (%) Control Misting Irrigation

  29. Epidemiology Time of inoculation and disease development • Replicated field trial • 3 spore concentrations • Incidence/severity • 5 inoculation times SSR incidence (%) 50% bloom 4 days past 100% bloom 50% & 100% bloom 100% bloom 100% bloom & 4 days later

  30. Epidemiology Soil conditions and apothecia formation • Replicated GC trial • Lab-produced sclerotia soil textures (clay: sand ratio) moisture regimes (% of saturation) • Time to apothecia formation • % apothecia formation Treatments in a 5 x 10 factorial: 1:0 2:1 1:1 1:2 0:1 100 100 - 75 75 100 - 50 50 100 - 25 25 75 - 50 75 - 25 50 - 25

  31. Epidemiology Soil conditions and apothecia formation • Soil moisture has significant impact • No significant effect of soil texture Apothecia formation (%) Clay:Sand ratio

  32. Epidemiology Soil conditions and apothecia formation • Continuous better than fluctuating moisture • No interactions a a b bcd Apothecia formation (%) cd ed ed def ef f % of soil saturation

  33. Epidemiology Soil conditions and apothecia formation • More apothecia in moderate texture soils • No interactions a ab bc c c # apothecia per sclerotium Clay:Sand ratio

  34. Epidemiology Soil conditions and apothecia formation • More apothecia per sclerotium in continuous moisture • No interactions a a abc ab cd bcd # apothecia per sclerotium de e e f % of soil saturation

  35. Epidemiology Forecasting efforts • Regional SSR risk (based on weather patterns) • Custom-made risk estimation (based on cultural practices) • Maps produced every three days during canola flowering stage (June 24 – July 21, 2008) • Program and database in: • http://www.ag.ndsu.edu/sclerotinia/sclerotinia/login.html

  36. Epidemiology Forecasting efforts

  37. Epidemiology Forecasting efforts SSR county prevalence and incidence, ND 2008 Incidence (%) Prevalence (%) County (%) Benson Bottineau Cavalier Ramsey Roseau Rolla Towner Ward 80 7 68 78 100 100 28 5 2 1 5 4 14 7 1 1

  38. Epidemiology Forecasting efforts Sclerotinia risk calculator:

  39. Epidemiology Forecasting efforts Custom-made risk estimation: • 1876 hits until end of August Custom-made risk estimation: • 46 registered users • No registered users from Roseau County • 50% visitors from Cavalier County • 30% forecasts in Cavalier called for moderate risk

  40. Epidemiology- Blackleg Cultural practices and disease development • Field surveys supplemented with grower information • Two year study • Shanna’s (MS thesis)

  41. Epidemiology- Blackleg PG and race identification • Field collection of leaf and stem lesions • Pathogenicity groups (GHSE inoculations) • Race identification in collaboration with French • Molecular work for mating type characterization • Virulence profile through GHSE inoculations • Characterization of reaction of commercial cultivars

  42. Epidemiology- Blackleg PG and race identification • PG identification based on reaction to three differentials: • - Westar - Quinta - Glacier • Race identification based on 12 differentials • Race nomenclature based on interacting genes • 4 races identified among 16 ND isolates • 67% isolates belong to race 1-2-3-(5)-(8)-9 • Race structure similar to that of Canada

  43. Epidemiology- Blackleg PG and race identification • >600 isolates ready for molecular work • 16 isolates in process of characterization • 30 commercial cultivars susceptible to isolates of PG-3 and PG-4 (GHSE trials) • Cultivar reaction to PG-T isolates in progress

  44. Epidemiology- Summary Sclerotinia stem rot: • SSR incidence reduced by 50% within 30 m • SSR requires 50 hours leaf wetness in 6 days • Role of cultivar height on SSR development not clear • Continuous soil moisture favor apothecia formation • Model to forecast probability of apothecia formation in progress • New risk-map was developed

  45. Epidemiology- Summary Blackleg: • 4 races of blackleg identified • Race 1-2-3-(5)-(8)-9 is more prevalent (67% of isolates) • Race structure similar to that of Canada • 30 commercial cultivars are susceptible to PG 3 and PG-4 isolates

  46. Disease management • Sclerotinia stem rot • Plant population studies • Biological control products • Fungicide evaluations

  47. Disease management Plant population studies • Factors: fungicide, plant population and row spacing • Field trial, Langdon 2008 • Incidence, severity, yield • Significant impact of plant populations and row spacing c b ab b a a SSR incidence (%) Plant population Row spacing (inches)

  48. Disease management Plant population studies • Yield affected by plant population and row spacing • No significant interactions a a a a b Yield (lb/A) b Plant population Row spacing (inches)

  49. Disease management Biological control products • Polyversum (P. oligandrum) • Endura (control) • Polyversum 30 days before flowering and/or at flowering a a a ab b SSR incidence (%) b b UNTC 1.5 oz F 3 oz F 1.5 oz BF 1.5 oz F 3 oz BF 3 oz F 3 oz BF Endura 6 oz F

  50. Disease management Biological control products • No significant impact on yield • No difference in oil production Yield (lb/A) UNTC 1.5 oz F 3 oz F 1.5 oz BF 1.5 oz F 3 oz BF 3 oz F 3 oz BF Endura 6 oz F

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