Epigenetic variation for agronomic improvement: an opportunity for vegetatively propagated crops

Crop breeding has been historically associated with genetic variation because genetic variants harboring traits with agronomic value can be artificially generated (e.g., hybrid crosses) and selected at the population (e.g., mass selection) or individual level (e.g., single seed descent) through classical crop breeding methods. Crop genetic improvement, however, has become increasingly difficult, and crop genetic diversity has been declining at an alarming rate, threatening world food security and sustainable development (Esquinas‐Alcázar, 2005). The stakes are high to find solutions. Cross breeding with closely related wild species, genomic selection informed by molecular markers and creation of genetically modified organisms are examples of ongoing research developments for crop improvement. Another potential research approach that is currently arising is epigenetics (Kenchanmane Raju and Niederhuth, 2018). Epigenetic variants in crops might represent an additional and timely resource for crop breeding. In this essay, we do not aim to comprehensively review the potential interest of epigenetics in agriculture but to outline the nature of some possible drawbacks, such as the instability of epigenetic marks, and opportunities, for example, clonal multiplication, associated with this potential. EPIGENETIC VARIANTS OF INTEREST FOR CROP BREEDING: WHERE ARE WE NOW?