Genetic Diversity and Population Structure of Sclerotinia sclerotiorum

Sclerotinia sclerotiorum is a globally distributed necrotrophic fungal pathogen with an exceptionally broad host range, affecting over 400 plant species and causing significant agricultural losses. Research has revealed a complex population structure shaped by both clonal propagation and sexual recombination. Populations often display high genotypic diversity with multiple multilocus genotypes (MLGs) co-existing in the same field, while linkage disequilibrium analyses suggest varying degrees of outcrossing among regions. Spatial genetic homogeneity across neighbouring fields contrasts with clear differentiation between distant climatic zones, indicating both local dispersal and long-range introduction events. Host association exerts a weaker influence on genetic partitioning than geography or climate, underlining the pathogen’s capacity for gene flow among diverse cropping systems. Understanding this genetic landscape is critical for devising durable control strategies and breeding resistant cultivars on a global scale.

Research from Nature Portfolio

A study of S. sclerotiorum populations from sunflower and cabbage in West Azarbaijan province of Iran used inter-simple sequence repeat (ISSR) markers and intergenic spacer (IGS) sequencing to characterise 136 isolates. Researchers identified 83 multilocus genotypes, observed a low clonal fraction and random association of loci consistent with frequent sexual recombination, and detected four IGS haplotypes with one predominant variant. The uniform spatial distribution of genotypes suggests a single introduction followed by local dispersal, indicating that coordinated management practices such as resistant cultivar deployment and fungicide application could be broadly effective across the region.

Genetic Diversity and Population Structure of Sclerotinia sclerotiorum publication trend

The graph below shows the total number of articles in genetic diversity and population structure of sclerotinia sclerotiorum across all publications each year (not limited to Nature Index journals).

Technical terms

Genetic diversity: Variation of genetic characteristics within and between populations of an organism.

Population structure: Non-random distribution of genetic variation across individuals or groups due to factors such as geography or host association.

Multilocus genotype (MLG): Unique combination of alleles across multiple genetic markers used to distinguish individuals or strains.

Mycelial compatibility group (MCG): Classification based on the ability of fungal isolates to anastomose and form a stable mycelial network, reflecting genetic relatedness.

Intergenic spacer (IGS): Non-coding region between ribosomal RNA genes used as a marker for haplotype identification.

Genome-wide association study (GWAS): Analysis linking genetic markers across the genome to phenotypic traits, such as virulence or aggressiveness.

References

1. Genetic structure of Sclerotinia sclerotiorum populations from sunflower and cabbage in West Azarbaijan province of Iran. Scientific Reports (2022).
2. Population and genome-wide association studies of Sclerotinia sclerotiorum isolates collected from diverse host plants throughout the United States. Frontiers in Microbiology (2023).
3. Morpho-Cultural and Pathogenic Variability of Sclerotinia sclerotiorum Causing White Mold of Common Beans in Temperate Climate. Journal of Fungi (2022).
4. Genetic Diversity Studies Based on Morphological Variability, Pathogenicity and Molecular Phylogeny of the Sclerotinia sclerotiorum Population From Indian Mustard (Brassica juncea). Frontiers in Microbiology (2018).