Nucellar embryony

Nucellar embryony (notated Nu+) is a form of seed reproduction that occurs in certain plant species, including many citrus varieties. During the development of seeds from plants that possess this genetic trait, the nucellar tissue which surrounds the megagametophyte can produce additional embryos (polyembryony) which are genetically identical to the parent plant. These nucellar seedlings are clones of the parent. By contrast, zygotic seedlings are sexually produced and inherit genetic material from both parents. Zygotic and nucellar embryos can occur in the same seed, and a zygotic embryo can divide to produce multiple embryos.