Effect of Temperature on Microdochium Disease Severity S. Stricker 1 - - PowerPoint PPT Presentation

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Effect of Temperature on Microdochium Disease Severity S. Stricker 1 - - PowerPoint PPT Presentation

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Effect of Temperature on Microdochium Disease Severity S. Stricker 1 , Dr. T. Hsiang 1 , Dr. A. Bertrand 2 1 University of Guelph, Guelph 2 Agriculture & Agri-Food Canada, Qubec City 2 3 Stricker, 2016 4 Hsiang, 2007 5 Hsiang, 2007 6

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Effect of Temperature on Microdochium Disease Severity

  • S. Stricker1, Dr. T. Hsiang1, Dr. A. Bertrand2

1 University of Guelph, Guelph 2 Agriculture & Agri-Food Canada, Québec City

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SLIDE 2

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SLIDE 3

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Stricker, 2016

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SLIDE 4

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Hsiang, 2007

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SLIDE 5

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Hsiang, 2007

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Hsiang, 2006

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Microdochium nivale

  • Fungal plant pathogen
  • Hosts include barley, oats,

wheat, and cool-season turfgrasses

  • Turfgrass diseases:
  • Pink snow mold after snowmelt
  • Fusarium patch/ Microdochium patch in spring and fall

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Fusarium or Microdochium patch?

Foot cell

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Fusarium spores Spores from pink snow mold

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Life Cycle of Microdochium nivale

Adapted from Tronsmo et al. 2001

Large bleached patches Pink-white mycelium Spores or mycelium infect new hosts Microdochium patch Oversummers in soil and thatch Infects new hosts, Microdochium patch Pink snow mold symptoms develop

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Creeping Bentgrass (Agrostis stolonifera)

  • Used as turfgrasses for fairways, tees and

putting greens

  • At low mowing heights, often invaded by

Annual bluegrass (Poa annua)

  • Susceptible to Microdochium patch
  • Inherent resistance genes vary by cultivar

http://www.mtviewseeds.com/images/photos/sub/bentgrass.jpg

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Microdochium nivale

  • In lab studies, the optimal growth

temperature for M. nivale is 22°C

  • The observed optimal temperature for

infection is between 0 and 15°C

  • (Brennan et al., 2003; Snider et al., 2000)

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SLIDE 12

https://www.ipcc.ch/publications_and_data/ar4/wg1/en/fig/figure-spm-6-l.png

+ 2°C + 5°C

2020-2029 2090-2099

Climate Change

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Projections of Surface Temperatures

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How might climate change affect

Microdochium nivale?

What will happen to M. nivale in usual Microdochium patch areas if exposed to hotter weather?

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Effect of temperature on M. nivale

  • Seven isolates of M. nivale grown

in Petri dishes, then exposed to 35ᵒC for various length of time

  • 1, 6, 12, 24, 36, 48, and 72 hours
  • Returned to 20ᵒC and monitored if

they continued to grow

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Effect of exposure to 35ᵒC

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20 40 60 80 100 10 20 30 40 50 60 70 80

Percent of actively growing colonies (%) Length of exposure to 35°C (h)

Survival of M. nivale colonies after exposure to 35°C

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Effect of exposure to 35ᵒC

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20 40 60 80 100 10 20 30 40 50 60 70 80

Percent of actively growing colonies (%) Length of exposure to 35°C (h)

Survival of M. nivale colonies after exposure to 35°C

Exposure time to kill 50% of the population = 22.3 hours

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Conclusions

  • What will happen to M. nivale in usual

Microdochium patch areas if exposed to hotter weather?

  • Longer exposure to high temperatures may kill

actively growing M. nivale hyphae

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How does Microdochium Patch

disease severity vary by cultivar?

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Materials and Methods

  • 18 Grass Cultivars
  • Creeping bentgrass (Agrostis stolonifera)
  • Colonial bentgrass (Agrostis capillaris)
  • Velvet bentgrass (Agrostis canina)
  • Annual bluegrass (Poa annua)
  • Inoculated with five isolates of M. nivale
  • Assessed for percent yellowing every 3

days

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Disease Severity Ranking

  • Average disease severity
  • f 18 cultivars was ranked
  • Average rank of 4 repeated

experiments was calculated

  • Low rank #= Low disease

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Cultivar Average Rank from 1 to 18

Greenspeed 6 D Focus 6 D Tyee 6 D Independence 6 D Kingpin 7 CD T1 7 CD Villa 7 CD Alpha 8 BCD Cato 9 ABCD Nordlys 10 ABCD Leirin 10 ABCD Declaration 10 ABCD Mackenzie 11 ABCD OO7 12 ABC Poa annua 13 AB Penncross 13 AB PennA4 14 A CY2 14 A

LSD (p<0.05) 5

Values with a letter in common are not significantly different.

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Cultivar Average Rank from 1 to 18

Greenspeed 6 D Focus 6 D Tyee 6 D Independence 6 D Kingpin 7 CD T1 7 CD Villa 7 CD Alpha 8 BCD Cato 9 ABCD Nordlys 10 ABCD Leirin 10 ABCD Declaration 10 ABCD Mackenzie 11 ABCD OO7 12 ABC Poa annua 13 AB Penncross 13 AB PennA4 14 A CY2 14 A

LSD (p<0.05) 5

  • Creeping

bentgrass

  • Colonial bentgrass
  • Velvet bentgrass
  • Annual bluegrass
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How might climate change impact

Microdochium Patch disease?

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Impacts of Climate Change

  • Plants in northern and temperate

climates undergo cold hardening

  • Stockpiling nutrients
  • Producing defence mechanisms against pathogens
  • Triggered by dropping temperatures and

decreasing day length

  • Climate change may lead to a disconnect

between temperature and day length

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Effects of temperature What will happen to Microdochium patch if conditions do not allow for cold hardening?

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Seeding

Conetainer Procedure

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0.04 g seed/cone 4 creeping bentgrass cultivars 20°C, 12 h photoperiod 2 wk 4°C, 10°C, 15°C, 20°C 12 h photoperiod 2 wk

Growth Temperature Treatments

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Conetainer Procedure

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0.04 g dried inoculum Incubated at 15°C % Yellowing assessed every 3rd day for 2 wk

Inoculation Disease Rating

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Results

Percent yellowing of turfgrass cultivars 9 days post inoculation with M. nivale after various pre-inoculation temperature treatments Treatment Alpha Focus Pencross Tyee Row LSD Treatment Mean 4°C 25ab 4b 28a 14a 20 18b 10°C 17b 22b 31a 26a 23 24b 15°C 13b 22b 27a 17a 18 20b 20°C 45a 50a 37a 22a 27 39a

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Values with a lowercase letter in common are not significantly different within column

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Conclusion

  • Pre-inoculation treatments of temperatures

<20°C decreased disease severity caused by

  • M. Nivale
  • What will happen to Microdochium patch if

conditions do not allow for cold hardening?

  • Disease symptoms may be more severe

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Resistance Activators

  • A synthetic chemical that is non-toxic to

plants and fungi that, when applied to a plant, activates natural resistance responses

  • The plant defences become

primed before the pathogen is present

  • Ready for battle!

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Civitas/Harmonizer™

  • Resistance Activator
  • Not a fungicide, no fungicide resistance

Effective controls on creeping bentgrass of:

  • Brown patch (Rhizoctonia solani)
  • Dollar spot (Sclerotinia homoeocarpa)

Developed by PetroCanada

  • Food-grade isoparaffins
  • Pigment dispersal product

containing copper II

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How it Works

  • Induced systemic resistance (ISR)
  • Induced- caused by the application
  • Systemic- through the plant system
  • Resistance- Defence response occurs faster

when pathogen is present

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Materials and Methods

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5% Civitas 0.3% Harmonizer (label rate)

  • r Water

Growth Activator Inoculation Disease Rating

10°C or 20°C 12 h photoperiod 2 wk 20°C 12 h photoperiod 3 wk

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Results- Experiment 1

Percent yellowing of turfgrass cultivars 14 days post inoculation with M. nivale, treated with Civitas or water, under two temperature treatments Treatment Cato Kingpin L93 Macke nzie OO7 PennA4 V8 Mean 10ᵒC Civitas 0a 0a 2a 0a 0a 0a 0a 10ᵒC Water 0a 2a 2a 3a 2a 12a 2a 3 20ᵒC Civitas 83a 80a 77ab 55b 90a 87a 87a 80 20ᵒC Water 98a 98ab 100a 98ab 100a 98a 90b 97 LSD (p<0.05) 6 6 15 24 9 16 10 5

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  • Values with a letter in common are not significantly different.
  • Means are based on 3 replicates.
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Results

Percent yellowing of turfgrass cultivars 12 days post inoculation with M. nivale, treated with Civitas or water, under two temperature treatments Treatment Alpha Focus Indep Penn Poa annua T1 Tyee Mean 10ᵒC Civitas 1a 0a 5a 2a 7a 5a 2a 3 10ᵒC Water 27ab 45ab 60a 20ab 13ab 28ab 7b 29 20ᵒC Civitas 13a 22a 20a 12a 15a 12a 17a 16 20ᵒC Water 47ab 37ab 63a 35ab 22b 55ab 47ab 44 LSD (p<0.05) 17 45 85 26 16 38 18 12

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  • Values with a letter in common are not different within row
  • Means are based on 3 replicates.
  • Indep= Independence, Penn= Penncross
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Disease Suppression 12 days post inoculation

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Average percent disease suppression by Civitas + Harmonizer 10ᵒC 83% 20ᵒC 60% LSD (p<0.05) 18

  • Means are based on 7 cultivars
  • Effect of cultivar was not significant (p>0.05)
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SLIDE 37

Disease Suppression 12 days post inoculation

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Percent disease suppression by Civitas + Harmonizer Experiment 1 Experiment 2 10ᵒC 81 83 20ᵒC 18 60 LSD (p<0.05) 31 18

  • Means are based on 7 cultivars
  • Effect of cultivar was not significant (p>0.05)
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Results

  • Most cultivars expressed less symptoms at 10°C

than 20°C

  • Civitas +Harmonizer 

Symptoms

  • C+H suppressed more disease symptoms at 10°C
  • Percent yellowing varied by cultivar

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How does this apply to the future?

Global temperature increase M. nivale inoculum Lack of cold hardening conditions Microdochium patch Civitas+ Harmonizer Microdochium patch (but works better at cool temp)

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Future Work

  • Continued Field Testing
  • Analysis of data on increased CO2 effect on M.

nivale disease and turfgrass biochemistry

  • Analysis of RNA expression in creeping

bentgrass inoculated with M. nivale

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Acknowledgments

Funding

  • Petro Canada
  • Canadian Turfgrass Research Foundation
  • Natural Sciences and Engineering

Research Council of Canada

People

  • Hsiang Lab
  • Bertrand Lab
  • GTI Staff

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Any Questions?

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Thank you for your time