Genome-wide Evidence of Host Specialization in Wild and Farmland Populations of the Fungal Leaf Spot Pathogen, Cercospora beticola

Taliadoros, Demetris; Potgieter, Lizel; Dhiman, Amar; Wyatt, Nathan A.; McMullan, Mark; Jung, Christian; Bolton, Melvin D.; Stukenbrock, Eva H.

doi:10.1093/gbe/evaf053

Abstract

One of the most recent crop species to be domesticated is sugar beet (Beta vulgaris L. ssp. vulgaris Doell.), which was bred for high sucrose content within the last few centuries in Europe. Crop domestication can also lead to the evolution of novel pathogens, which may spread across large geographical distances with their crop host. In this study, we addressed the recent evolution of the fungal pathogen causing the disease Cercospora leaf spot, Cercospora beticola. This pathogen has become increasingly important in sugar beet and table beet production worldwide. We used genome sequences of 326 C. beticola isolates collected from 4 continents from 4 closely related Beta subspecies (3 domesticated and 1 wild). We applied population genomic analyses to identify signatures of population differentiation and host specialization in C. beticola populations derived from the cultivated and wild hosts. We found evidence that C. beticola populations in agro-ecosystems likely originate from sea beet-infecting isolates. Intriguingly, host jumps from wild to cultivated beet occurred in at least 2 independent events as evidenced by our population data of C. beticola from wild beet collected in the Mediterranean and the UK. We explore the occurrence of genetic variants associated with fungicide resistance and virulence and show that standing genetic variation in C. beticola populations from both wild and domesticated plants may serve as a reservoir of functionally important alleles. Overall, our results highlight the ability of C. beticola to invade the agro-ecosystem and establish new populations, demonstrating the rapid adaptation potential of the species.

Keywords

fungal pathogen evolution; plant disease; beet; selective sweeps; population divergence

Published in

Genome Biology and Evolution
2025, volume: 17, number: 4, article number: evaf053
Publisher: OXFORD UNIV PRESS

SLU Authors

Potgieter, Lizel
- Kiel University (CAU)
- Max Planck Institute for Evolutionary Biology

UKÄ Subject classification

Agricultural Science
Evolutionary Biology

Publication identifier

DOI: https://doi.org/10.1093/gbe/evaf053

Permanent link to this page (URI)

https://res.slu.se/id/publ/141812