adventive embryony

(adventitious embryogenesis) The formation of an embryo in some position other than within an embryo sac. It is a form of *apomixis . Adventive embryos may develop from somatic cells of the nucellus or chalaza (*apospory ) and may occur together with a normal zygotic embryo. One seed can contain several embryos, as is often the case in Citrus seeds. Alternatively an embryo may develop from the unreduced egg cell (*diplospory ).