Diploid F1 Hybrid Breeding: A Paradigm Shift in Potato Breeding

Considering the high yield and great nutritive value, potatoes are the world’s fourth most vital food crop and the largest non-cereal crop. The cultivated potato (Solanum tuberosum L.) is an asexually propagated, highly heterozygous, and polysomic autotetraploid (2n = 4x = 48) with a genetically complex structure. Moreover, low recombination rates and long generation breeding cycles make it difficult to fix favourable alleles to accomplish genetic gains, posing a challenge for potato breeders and geneticists. Diploid potatoes provide a simplified genetic system, genetic diversity, and many economically important traits needed for variety development. To enhance genetic gain in potato breeding, there is a need to shift the potato from a tuber-propagated tetraploid crop into an inbred-line-based diploid crop. However, diploid potatoes and dihaploids are self-incompatible and inbreeding results in severe depression in potatoes. Nevertheless, studies have shown good hybrid vigour by crossing diploid inbred potato lines. Hybrid breeding speeds up introducing desired traits into the breeding material to increase tuber traits, pathogen resistances, and potato yields. Hybrid true potato seeds (HTPS) may serve as the basis for new planting techniques and high-tech potato cropping systems. The number of seed tuber vegetative multiplication cycles in the field could be drastically reduced or eliminated using HTPS.