The new European yellow rust situation in a global perspective

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1 The new European yellow rust situation in a global perspective March 8, 2016 Prof. Mogens Støvring Hovmøller Aarhus University/ Global Rust Reference Center (GRRC), Denmark mogens.hovmoller@agro.au.dk

2 Key collaborators Ravi Singh, CIMMYT Dave Hodson, CIMMYT Kumarse Nazari, ICARDA Claude Pope, INRA (F) Sarah Holdgate, NIAB (UK) James Brown, JIC (UK) Diane Saunders, JIC (UK) Kerstin Flath, JKI (D) Jonathan Yuen, Uppsala University (S) Hans Thordal-Christensen (DK, KU) Thomas Sicheritz-Ponten (DK, CBS-DTU) Finn Borum (DK, Sejet Plant Breeding) Ahmed Jahoor (DK, Nordic Seed A/S) > 40 people who submitted wheat rust samples from Asia, Africa and South America Global Rust Reference Center (GRRC) The team March 2014

3 The Borlaug Global Rust Initiative Network & Global Rust Reference Center Aarhus University Denmark

4 GRRC research activities at glance Pathogen genotyping/phenotyping/ using both molecular and epidemiological techniques [research in pathogen diversity, evolution, spread, and host-pathogen interactions] Pathogen epidemiology and genetics [e.g., role of aggressiveness, temperature adaptation and genetic basis for important traits like virulence and aggressiveness, - using Berberis spp. as sexual host] Improved methods for disease resistance phenotyping [in collaboration with commercial plant breeding companies and international institutions]

5 Dissemination, training and ressources Extension farmers - breeding companies (Scandinavia) [Results about changes in (yellow) rust susceptibility in commercial crop varieties] CIMMYT/ICARDA/FAO (global) Data management via the WheatRustToolbox ( [results about disease incidence and severity of stem/leaf/yellow rust and pathogen race diversity and dynamics] Teaching/training [PhD students, visiting scientists, Univ. courses] Collect and maintain genetic stock isolates [facilitate resistance breeding and research] Access to rust quarantine facilities in green house and lab

6 Wheat rust quarantine facility and liquid N storage of stock isolates

7 Yellow rust epidemiology is changing Increasingly often observed on the newly autumn-sown wheat and triticale Earlier and more severe epidemics in spring Triticale: Denmark, 11th March 2014

8 Yellow rust epidemiology is changing Increasingly often observed on the newly autumn-sown wheat and triticale Earlier and more severe epidemics in spring Triticale Denmark March 1st 2016

9 Yellow rust epidemiology is changing Increasingly often observed on the newly autumn-sown wheat and triticale Earlier and more severe epidemics in spring Telial spore stage commonly observed (yellow rust turning black ) Wheat: The Nederlands, 1st April 2014 Photo: Lise Nistrup Jørgensen

10 Yellow rust epidemiology is changing Disease increasingly often observed on the newly autumn-sown wheat and triticale Earlier and more severe epidemics in spring dramatic changes in susceptibility Telial spore stage commonly observed Dramatic changes in resistance and susceptibility crop and variety level Typical triticale in the past Typical triticale in

11 Organic grown triticale, Sweden, June 2015

12 7 of 8 years with av. temp < 0C: None or weak attack 8 of 11 years with av. temp >2.5 C: Severe attack 14 Yellow rust epidemiology in Denmark YR severity (%) on Anja (standard) in non-fungicide plots. Av locations per year,

13 Changes in race distribution in Europe

14 Changes in race distribution in Europe* Source: Hovmøller et al *Note: Countries not equally represented across the years due to differences in disease prevalence, sampling intensity and size of differential set (virulence assessment).

15 Changes in race distribution in Europe* Source: Hovmøller et al Aggressive strains spreading world-wide since 2000 New race giving rise to widespread epidemics on triticale Warrior and Kranich races changing the epidemiology on wheat in Europe

16 Changes in race distribution in Europe* Old European population: Low SSR diversity within and between races New European population: Higher SSR diversity within and between races

17 World-wide population of the yellow rust fungus subdivided into at least six distinct genetic groups (Ali et al. 2014; PLOS Pathogens)

18 Tracking the source populations of the new invasive races: Himmalayas _Middle East _Med &CA _Europe

19 Tracking the source populations of the new invasive races: Himmalayas _Middle East _Med &CA _Europe

20 Tracking the source populations of the new invasive races Distribution of multilocus genotypes detected within Warrior & Kranich Warrior race Kranich race Multilocus genotype Country Total Denmark France MLGW-1 Germany Portugal Spain United Kingdom France MLGW-2 Germany Sweden United Kingdom MLGW-3 Denmark MLGW-4 United Kingdom MLGW-5 United Kingdom MLGW-6 Denmark Denmark MLGK-1 Finland Sweden MLGK-2 Denmark Finland MLGK-3 Sweden MLGK-4 Finland MLGK-5 Sweden Total Suggesting aerial dispersal of spores from genetically diverse source populations

21 Details of new races in northern Europe in 2015

22 Details of new races in northern Europe in 2015

23 Details of new races in northern Europe in 2015 Triticale, Sweden, June 2015 Hereford, Sweden, June 12, 2015

24 Spring 2016 what s next? 1st week March: 30 samples entering multiplication 2nd week March: DNA extraction and PCR Triticale, Denmark, 29th February rd week March: SSR genotyping 2nd spore multiplication 1st week April SSR genotyping results analysed Differential sets inoculated 3rd week April First race data available Additional diff. sets inoculated End of April 2nd newsletter release and updates on

25 Rust-resistance phenotyping in inoculated nurseries using local races Inoculation in April using infected seedlings carying specific races

26 Disease assessment* 3-4 times in growing season * % green leaf area affected and infection type 0-9

27 Improved phenotyping techniques in lab and green house Chris Sørensen Sørensen et al., 2016: Evaluation of spray and point inoculation methods for the phenotyping of Puccinia striiformis on wheat. Plant Disease (first look)

28 Improved phenotyping techniques in lab and green house Adult plants in quarantine green house ( )

29 Resistance phenotyping during winter using adult plants in quarantine green house ( )

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32 Research on wheat stem rust Mehhran Patpour Photo: Svend Tveden Nyborg

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34 Overall summary New races of yellow rust more variable and aggressive than previous European races The pathogen spread longer, wider and more rapidly DNA genotyping coupled with race phenotyping necessary for understanding pathogen diversity and dynamics Warrior and Kranich races previous resistant varieties became susceptible and vice versa susceptible became less susceptible or resistant Generally poor resistance in Triticale many sources of resistance in wheat, even to new (exotic) races New methods for disease resistance phenotyping are promising and in progress Sustained European collaboration essential