A 2025 Nature Communications study used Pinot Noir pedigrees and population genomics to compare how crossing, selfing and clonal propagation reshape grapevine heterozygosity and genetic burden.
Selfing reduces heterozygosity while cloning preserves it
Clonal propagation can preserve valuable heterozygous genotypes but also masks recessive deleterious variants. Selfing exposes and can purge part of that burden, while also creating inbreeding risk.
PN40024 purged much of its heterozygous burden
Relative to its parent HE, the selfed PN40024 lineage reduced heterozygous deleterious SNPs by 62% and structural variants by 65%. Some burden also shifted into homozygous states, so purging was not complete.
Why did 4.3% of the genome remain heterozygous after nine selfing generations?
The earlier article attributed those regions mainly to essential or sex-determination genes. The study instead emphasizes tightly linked large-effect deleterious and structural variants in repulsion phase, which can preserve heterozygous blocks because either homozygous alternative carries a cost.
Crossing, cloning and selfing therefore provide different tools rather than a single best strategy: introduce variation, preserve elite combinations, or expose genetic burden depending on the breeding objective.
For related context, see Was Cupuaçu Domesticated 8,000 Years Ago? What the Genome Actually Shows.
For related context, see How Are Japanese Soybeans Genomically Different? A 462-Accession Pangenome—and Two Author Corrections.
For related context, see Morning Female, Later Male: SDMYB Underlies Avocado Flowering Type and an Ancient 44-Million-Year Polymorphism.
Reference
- Xiao H et al. Impacts of reproductive systems on grapevine genome and breeding. Nature Communications. 2025;16:2031. https://doi.org/10.1038/s41467-025-56817-7
Comments