Harnessing Apomixis to Improve Crops

Apomixis is a naturally occurring reproduction mode in flowering plants that results in embryo formation in absence of both meiosis and eggcell fertilization. Apomixis results from the combination of two processes: apomeiosis (unreduced embryosac formation due to diplospory or apospory) and parthenogenesis (development of an embryo without fertilization). Seed-derived progenies of an apomictic plant are genetically identical to the maternal parent, i.e., they are clonal in origin. The impact on agriculture of the introgression of apomixis into sexual crops, will be revolutionary. In fact, apomixis will allow clonal seed production and thus enable efficient and consistent yields of high quality seeds, fruits and vegetables at lower costs. The development of apomixis technology will reduce cost and breeding time also avoiding the complications typical of sexual reproduction (e.g., incompatibility barriers) and vegetative propagation (e.g., viral transfer). Progresses in the search for apomixis genes obtained by several groups could allow the manipulation of apomixis and its transfer to crop species where the apomixis system is not present and to revolutionize modern agriculture. Moreover, when coupled with male-sterility systems, apomictic reproduction (with no need for male contribution) could help in addressing issues related to transgene escape from GM crops to organic or conventional crops, and thereby allow for better coexistence systems.

Keywords: Apomeiosis, Apomixis, Asexual reproduction, Fertilization, Hybrid vigor, Inbreeding depression, Meiosis, Parthenogenesis, Plant reproduction, Sexual reproduction.