EuroBlight, a late blight monitoring network for Europe, is continuously examining the ongoing evolution of the European population of the potato late blight pathogen. Euroblight has now released a report detailing the results of the 2021 monitoring activities. Approximately 2500 samples from 26 countries were genotyped.
The key findings are as follows:
- The blight pressure in 2021 was higher than average across many parts of Europe.
- Disease outbreaks from 26 countries were sampled by several groups in 2021 resulting 2492 genotyped samples.
- Around 72% of these samples were of defined clonal lineages observed in previous seasons while the rest consisted of ephemeral, genetically diverse ‘Other’ types consistent with oospore-borne inoculum.
- The proportions of the main clones in the 2021 population were broadly similar to those reported in 2020. Newer clones EU_41_A2, EU_37_A2, EU_36_A2, EU_43_A1, EU_44_A2 and EU_45_A2 made up 48% of the 2021 population. These clones are displacing the established 13_A2, 6_A1 and 1_A1 clones which caused only 17% of the blight lesions sampled in 2021.
- Regional trends in the type and proportion of clones compared to sexual recombinant populations were observed across Europe. For example, ‘Other’ genotypes more prevalent in Denmark, Norway, Sweden and Finland than across countries to the west of Europe.
- Some implications of these displacements and ongoing changes are discussed.
Photo: Credit and courtesy Wageningen University & Research (WUR)