diplospory

Diplospory is a form of apomictic (asexual) seed formation in flowering plants. In diplospory the embryo sac develops from the megaspore mother cell without undergoing meiosis, so the embryo sac is unreduced (2n). The egg cell within this mature embryo sac is also unreduced and can develop into an embryo without fertilization (parthenogenesis). Fertilization of the central cell to form endosperm may be required in many diplosporous species (pseudogamy), whereas some taxa can form autonomous endosperm.

Diplospory is a subset of gametophytic apomixis, in contrast to apospory, where the embryo sac arises from somatic nucellar tissue rather than from the megaspore mother cell. In both cases the resulting embryo is typically genetically identical to the mother plant, thereby bypassing normal sexual reproduction. However, endosperm development and seed viability can vary, with some diplosporous species showing autonomous endosperm and others requiring fertilization for successful seed development.

Occurrence and significance vary among plant groups. Diplospory has been documented in several families, with Taraxacum (dandelions) serving as a classic example. It contributes to reproductive assurance and rapid colonization, preserving maternal genotypes across generations, while potentially limiting genetic diversity unless mutations or polyploid changes occur. Research on diplospory informs studies of evolution, adaptation, and breeding strategies that utilize apomictic seed production.