Mitochondrial genome is paternally inherited in Cucumis allotetraploid (C. × hytivus) derived by interspecific hybridization

• We examine the nucleotide polymorphisms of mitochondria in intraspecific crosses.
• The synthetic allotetraploid is from a wide cross between Cucumis species with different numbers of chromosome.
• This intraspecific cross also showed differential transmission of the three genomes.

Paternal transmission of the mitochondrial (mt) genome in cucumber (Cucumis sativus L.) was revealed previously using intraspecific crosses. The present study reports the first paternal transmission of mtDNA observed between Cucumis species. Mitochondrial primers specific to nad1, cob, and nad7 were used to amplify the DNAs from the female parent (C. hystrix), male parent (C. sativus) and the allotetraploid (C. × hytivus) derived the interspecific hybridization. By sequence alignment, we found that the explicit nucleotide polymorphisms of the allotetraploid were all inherited from male parent, C. sativus. Similar experiment with chloroplast (cp) genome was conducted and the results showed that while mtDNA was paternally inherited, cpDNA was still maternally inherited between Cucumis species. This work provides novel evidence of paternal transmission of the mitochondrial genome between plant species and lays the foundation for further research on the genetic mechanism of mitochondrial transmission in Cucumis.