Interspecific somatic hybridization has been performed in potato
breeding experiments to increase plant resistance against biotic and
abiotic stress conditions. We analyzed the mitochondrial and plastid
genomes and 45S nuclear ribosomal DNA (45S rDNA) for the cultivated
potato (S. tuberosum, St), wild potato (S. commersonii,
Sc), and their somatic hybrid (StSc). Complex genome components and
structure, such as the hybrid form of 45S rDNA in StSc, unique plastome
in Sc, and recombinant mitogenome were identified. However, the
mitogenome exhibited dynamic multipartite structures in both species as
well as in the somatic hybrid. In St, the mitogenome is 756,058 bp and
is composed of five subgenomes ranging from 297,014 to 49,171 bp in St.
In Sc, it is 552,103 bp long and is composed of two sub-genomes of
338,427 and 213,676 bp length. StSc has 447,645 bp long mitogenome with
two subgenomes of length 398,439 and 49,206 bp. The mitogenome structure
exhibited dynamic recombination mediated by tandem repeats; however, it
contained highly conserved genes in the three species. Among the 35
protein-coding genes of the StSc mitogenome, 21 were identical for all
the three species, and 12 and 2 were unique in Sc and St, respectively.
The recombinant mitogenome might be derived from homologous
recombination between both species during somatic hybrid development.