Unveiling the hidden codes: a review of variability and ecological epigenetics after 20 years of studies on potato

The cultivated potato Solanum tuberosum subsp. tuberosum L. retains an important reservoir of genetic diversity in its secondary gene pool. More than 100 wild species of potato, with ploidies from 2x to 6x, grow in the Americas. These species are adapted to contrasting environments, showing wide phenotypic diversity in leaf, floral, and tuber morphology. The taxonomic relationship among species is not clear, mainly due to little chromosomal differentiation and pervasive interspecific hybridization. This review summarizes data from more than 20 years of studies on genetic and epigenetic variability of potato species, highlighting the importance of epigenetic variability, hybridization, and polyploidization in the evolution and diversification of this group. The epigenetic diversity of these species remains poorly characterized. This review addresses the ecological implications of epigenetic variation, emphasizing its role in plant adaptation to changing environments. Finally, the study proposes a model that integrates epigenetic variability into the evolution of natural potato populations, highlighting its potential for rapid adaptation and phenotypic differentiation.