Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.
ROBERT A. MCINTOSH THE UNIVERSITY OF SYDNEY PLANT BREEDING INSTITUTE COBBITTY, NSW AUSTRALIA Historical Overview of Stripe...
TAXONOMY OF THE PATHOGEN <ul><li>Reviewed and revised by Liu & Hambleton (2010) </li></ul><ul><li>- Uredo glumarum  Schmid...
SPECIES SPECIALIZATION <ul><li>Liu & Hambleton (2010) using its & beta-tubulins </li></ul><ul><li>- P. striiformis  on the...
f. sp. tritici f. sp. hordei f. sp. pseudohordei -  PNW21 ? Puccinia striiformis formae speciales
Almost worldwide Historically considered to favour cooler areas Recent outbreaks defy assumptions Are there unique aspects...
Up to 50%, but occasionally higher Stripe rust losses
 
 
DISEASE CYCLE <ul><li>Epidemic Phase – during the cropping cycle </li></ul><ul><li>Survival Phase  –  during the non-cropp...
LIFE CYCLE OF A RUST PATHOGEN
EPIDEMIOLOGY <ul><li>Role of the sexual hosts </li></ul><ul><ul><ul><li>What species of barberry? </li></ul></ul></ul><ul>...
PATHOGENIC VARIATION IN  PST <ul><li>Differential sets for seedling assays </li></ul><ul><li>Why Have differential sets? <...
 
GENETICS OF RESISTANCE <ul><li>Seedling resistances </li></ul><ul><ul><ul><li>We still do not know the genetic bases of re...
DURABILITY OF RESISTANCE <ul><li>Resistances/resistance genes effective at the seedling stage have not proven to be durabl...
BREEDING FOR STRIPE RUST RESISTANCE <ul><li>There is no shortage of resistance </li></ul><ul><li>Resistance must be in the...
POST-RELEASE VARIETY MANAGEMENT <ul><li>Avoid/Remove/Prevent/Discourage highly susceptible varieties – the bushfire effect...
WHAT MAKES RUST EXCITING
Upcoming SlideShare
Loading in …5
×

Historical Overview of Stripe Rust Research

1,296 views

Published on

Robert A. McIntosh
Professor Emeritus
Plant breeding Institute
The university of Sydney
Cobbitty, NSW
Australia

  • Be the first to comment

  • Be the first to like this

Historical Overview of Stripe Rust Research

  1. 1. ROBERT A. MCINTOSH THE UNIVERSITY OF SYDNEY PLANT BREEDING INSTITUTE COBBITTY, NSW AUSTRALIA Historical Overview of Stripe Rust Research
  2. 2. TAXONOMY OF THE PATHOGEN <ul><li>Reviewed and revised by Liu & Hambleton (2010) </li></ul><ul><li>- Uredo glumarum Schmidt - before 1819 </li></ul><ul><li>- P. glumarum Eriks. & Henn. 1894 (until the 1950s) </li></ul><ul><li>- Puccinia striaeformis Westend. 1954 </li></ul><ul><li>- P. striiformis </li></ul>
  3. 3. SPECIES SPECIALIZATION <ul><li>Liu & Hambleton (2010) using its & beta-tubulins </li></ul><ul><li>- P. striiformis on the triticeae </li></ul><ul><li>- P. gansensus on achnatherum inebrians </li></ul><ul><li>P. striformoides on Dactylis glomerata </li></ul><ul><li>P. pseudostriiformis on Poa. spp. </li></ul>
  4. 4. f. sp. tritici f. sp. hordei f. sp. pseudohordei - PNW21 ? Puccinia striiformis formae speciales
  5. 5. Almost worldwide Historically considered to favour cooler areas Recent outbreaks defy assumptions Are there unique aspects of environment that determine distribution? Are current races more adapted to high temperatures What factors determine distribution within regions? Puccinia striiformis tritici Distribution
  6. 6. Up to 50%, but occasionally higher Stripe rust losses
  7. 9. DISEASE CYCLE <ul><li>Epidemic Phase – during the cropping cycle </li></ul><ul><li>Survival Phase – during the non-cropping season </li></ul><ul><li>The rust pathogens are obligate parasites and need living plants to survive in the uredinial stages </li></ul><ul><li>During non-optimal periods one generation of the fungus may take longer than 1-2 weeks </li></ul>
  8. 10. LIFE CYCLE OF A RUST PATHOGEN
  9. 11. EPIDEMIOLOGY <ul><li>Role of the sexual hosts </li></ul><ul><ul><ul><li>What species of barberry? </li></ul></ul></ul><ul><ul><ul><li>Where? </li></ul></ul></ul><ul><ul><ul><li>Are they important in relation to Pst on wheat? </li></ul></ul></ul><ul><li>Role of asexual hosts </li></ul><ul><ul><ul><li>What grass species? </li></ul></ul></ul><ul><ul><ul><li>Where? </li></ul></ul></ul><ul><ul><ul><li>Are they important in rust survival? </li></ul></ul></ul><ul><ul><ul><li>VOLUNTEER WHEAT IS PROBABLY THE MAIN SOURCE OF INOCULUM </li></ul></ul></ul>
  10. 12. PATHOGENIC VARIATION IN PST <ul><li>Differential sets for seedling assays </li></ul><ul><li>Why Have differential sets? </li></ul><ul><li>Genetics of the differentials </li></ul><ul><li>Repeatability of data </li></ul><ul><li>Naming races </li></ul><ul><ul><ul><li>German, European, North American, Indian, Chinese </li></ul></ul></ul><ul><ul><ul><li>Environmental conditions for testing </li></ul></ul></ul><ul><ul><ul><li>Differentials for field assays??? </li></ul></ul></ul>
  11. 14. GENETICS OF RESISTANCE <ul><li>Seedling resistances </li></ul><ul><ul><ul><li>We still do not know the genetic bases of resistance in differentials </li></ul></ul></ul><ul><ul><ul><li>Problems in international race variation </li></ul></ul></ul><ul><ul><ul><li> Adult plant resistances </li></ul></ul></ul><ul><ul><ul><ul><ul><li>Recognized from the 1960s - Zadoks, Stubbs, Sharp, Bingham, Law </li></ul></ul></ul></ul></ul>
  12. 15. DURABILITY OF RESISTANCE <ul><li>Resistances/resistance genes effective at the seedling stage have not proven to be durable. There are many genes of this type </li></ul><ul><li>At least some resistances/resistance sources for APR have proven durable. There are many genes of this type </li></ul><ul><li>BUT not all gene/gene sources for APR are durable </li></ul>
  13. 16. BREEDING FOR STRIPE RUST RESISTANCE <ul><li>There is no shortage of resistance </li></ul><ul><li>Resistance must be in the best varieties </li></ul><ul><li>We must have rust to select for resistance (even when we have markers!!) </li></ul><ul><li>Value of international testing </li></ul><ul><li>Problems of lack genetic diversity </li></ul><ul><ul><ul><li>Megavarieties </li></ul></ul></ul><ul><ul><ul><li>Copycat breeding </li></ul></ul></ul>
  14. 17. POST-RELEASE VARIETY MANAGEMENT <ul><li>Avoid/Remove/Prevent/Discourage highly susceptible varieties – the bushfire effect!! </li></ul><ul><li>Need to monitor pathogen populations over space and time – using differentials or markers </li></ul><ul><li>Need to monitor relative disease responses in relation to variety make-up, changing agronomic practices, climate change, neighbours. Rust is a social issue </li></ul><ul><li>At the international level need to build up a co-operative attitude to information sharing, mutual sharing of risk analysis, and trust </li></ul>
  15. 18. WHAT MAKES RUST EXCITING

×