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GRRC report of yellow and stem rust genotyping and race analyses 2021

This report presents molecular genotyping and race typing results with a focus on samples of rust infected wheat, barley and triticale collected in 2021 across four continents, i.e., Europe, Asia, Africa and South America.

Stem Rust. Photo Jens G. Hansen

The report is based on rust samples from many regions of the world, which has only been possible with the impressive contribution of a huge number of collaborators, who have assisted in sample collection in 2021.

Read the full report in pdf

Key highlights yellow rust

  • A new incursion of a highly virulent race in East Africa represented a new genetic group, termed PstS16.

  • It was detected in December 2020 in Ethiopia and became widespread in farmer’s fields and experimental plots in 2021, but not detected in neighboring countries. PstS16 was also widespread in Afghanistan in 2021.

  • Genetic group PstS13 spreads to new areas in South America, including Paraguay, where yellow rust was detected for the first time. A single race/genotype is still prevalent although local variants have been observed. PstS13 has mainly affected triticale and durum wheat in Europe and bread wheat in South America and Australia.

  • PstS14 was widespread in Iraq, which represents first detection of this genetic group in Asia. Present in Europe and northern Africa since 2016.

  • PstS10 was the most prevalent genetic group in Europe. At least 4 races were detected, each adapted to local, widely grown wheat varieties.

  • PstS11 and PstS1/PstS2 were confirmed in multiple countries in East Africa.

  • PstS7 (Warrior race) was less prevalent than in previous years, however, up to now detected in Europe, northern Africa and South America.

  • Additional genetic groups, including groups which have not yet been named (collectively termed ‘Other’), were either absent or detected in low frequencies.

  • Samples from Nepal were genetically different from all named groups and revealed high pathogen diversity in this area.

Key highlights stem rust

  • Three genetic groups of stem rust were prevalent in Europe. Additional spread was observed in France in particular, but also in other countries in Central/West Europe.

  • Clade III-B (race TTRTF) was widespread in southern part of Europe, and in 2021 also detected in Tunisia and Switzerland. Since first detection in Sicily in 2016, we have confirmed TTRTF in 9 countries in Europe, and 4 countries in Africa/Asia.

  • Clade IV-F (race TKKTF) was detected in 4 African and 13 European countries in 2021. Previously, we have also detected TKKTF in Azerbaijan, Egypt, Iran, Iraq and Tajikistan.

  • Clade IV-B (races TKTTF, TKRTF and TTTTF) was observed in Tanzania and Tunisia and in 8 European countries in 2021. TKRTF was observed in a single isolate from Spain; TTTTF was observed in East Africa but not in Europe.

  • Clade I (Ug99) was not observed outside East Africa.

You can find the results on maps and charts via these direct links:

Contact

E-Mail: mogens.hovmoller@agro.au.dk

E-Mail: jensg.hansen@agro.au.dk

Report in pdf

Read the full report in pdf

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