Europe
March 25, 2020

EuroBlight, the international consortium tracking the spatial distribution of Phytophthora infestans, the pathogen responsible for late blight in potato crops, has published the results of its extensive 2019 survey work, revealing the distribution and diversity of dominant clones in the crop.

EuroBlight’s extensive team of disease ‘scouts’ collected around 1,800 samples during the 2019 season, pressing disease lesions on to special cards which then underwent DNA fingerprinting in the labs at the James Hutton Institute in Scotland and INRAE in France. The DNA data was then used to define the clonal lineages of the pathogen and combined with geolocation data to plot the diversity across Europe, reports the James Hutton Institute website.

EuroBlight’s key findings:

• Three emerging clones of P. infestans  (37_A2, 36_A2 and 41_A2) increased their combined frequency from 10% in 2016 to 40% of the population in 2019.
• Regional differences exist in the frequency of the emerging clones e.g. the frequency of clone 37_A2 has declined to 10% or less between 2018 and 2019 in the Netherlands and Britain, but remains 25% in Belgium and France.  
• These recent clones are displacing the established 13_A2, 6_A1 and 1_A1 clones which reduced in frequency from 60 to 30% of the samples collected between 2016 and 2019
• A quarter of the population comprised ephemeral, genetically diverse isolates consistent with oospore-borne inoculum.
• A regional pattern in the dominance of clones versus sexual recombinants was observed across Europe. Some implications of these displacements and ongoing changes are discussed.
• The weather in 2019, was very dry and unfavourable for late blight development in some regions but very conducive for blight in other regions like Denmark and Northern Britain.

For more information:

• Read more on the EuroBlight website here
• Read more on the James Hutton Institute website here
• You can download the complete news story in pdf format here: Euroblight_Monitoring_2019

Website: http://www.endure-network.eu

Published: March 25, 2020