Genetic makeup of autonomous endosperm in Hieracium

Apomixis (asexual seed formation) generates clonal plants with a maternal genotype. Apomictic Hieracium subgenus Pilosella species mitotically form female gametes, with the seed’s embryo and endosperm developing autonomously (without fertilisation). Henderson et al. examine expression of the dominant autonomous endosperm (AutE) trait in progeny of crosses characterised by female gametes forming mitotically or sexually via meiosis, and requiring fertilisation for embryo formation.

Concluding that the mode of female gamete formation does not significantly influence AutE expressivity, the authors suggest that further research into other genetic factors in addition to AutE could help to establish the high trait expression found in apomicts. A linkage group bearing the AutE locus was identified.