Inheritance of the rough skin character in peach

Pubescence in peach (Prunus persica) fruit is controlled by the g locus, with the homozygous recessive alleles (gg) resulting in the glabrous-skinned nectarine while the heterozygous or homozygous dominant alleles (GG or Gg) producing the hairy peach.
Differing from normal peaches and nectarines that have long or no trichomes (hairs) on their fruit, respectively, accessions with the rough skin character have short epidermal stubs visible under a microscope, but which is rough to the touch and appears dull compared to that of hairy peach or shiny nectarine.
A pleiotropic effect is lack of hairs on the dormant leaf and flower buds, making them noticeably shiny to the naked eye, unlike normal peaches and nectarines.
The rough skin character appeared in 3 of 70 seedlings from the cross of ‘Pekin’ × ‘Durbin’. The remaining seedlings all produced normal peaches.
Selfed seedlings of ‘Pekin’ and ‘Durbin’ have not expressed the recessive form of the gene.
Possibly a limb of the ‘Pekin’ tree (now gone) used for the crosses had mutated to the recessive form at one or both loci.
The origin of the mutation is unclear.
The homozygous rough skin progeny would have then been inadvertent self-pollinations rather than hybrids, since none of them segregated for nectarine.
Sibling F₂ progenies segregated for peach and nectarine, and in one case, for rough skin as well, indicating the cross was valid.
Results from numerous crosses and F₂ populations indicate this trait, designated as “roughskin”, is controlled by a single recessive gene, which is hereby designated rs. Nectarines homozygous for this gene (i.e., ggrsrs) have glabrous buds, but otherwise appear as normal nectarines.
Possible use of the rough skin trait in breeding was discussed.

X International Peach Symposium

Chunxian Chen, W.R. Okie

Prunus persica, trichome, glabrous, nectarine, fruit cracking, periclinal chimera

https://doi.org/10.17660/ActaHortic.2022.1352.53