In a type of apomixis known as adventive embryony, the embryos develop directly from (JRF Plant Science 2019)

✅Explanation: In adventive embryony, embryos develop directly from the diploid cells of the nucellus or integuments of the ovule, bypassing the usual process of fertilization and meiosis.

📌Other Options Explanations:
Zygote: A zygote is formed by the fusion of male and female gametes.
Synergids or antipodals in an embryo sac: These are part of the female gametophyte and are not directly involved in adventive embryony.
Accessory embryo sacs in the ovule: These are additional embryo sacs.

🔑Key Points:
-Apomixis: ''apo'' = without & ''mixis'' = mixing. It is a form of asexual reproduction that results in the formation of seeds without fertilization (i.e without the fusion of male and female gametes). It is seen in plants of species Asteraceae & grasses.
-It is a form of asexual reproduction that mimics sexual reproduction.
-There are two kinds of apomixis in flowering plants: Agamospery and vegetative propagation

✏️Agamospermy is further divided into three types:
-Adventive embryonic
-Parthenogenesis
-Apospory & Apogamy

• Adventive embryonic:
-Formation of embryo directly from the diploid sporophytic cells (nucellus or integuments) of ovule (other than zygote) is called adventive embryony
-It is seen in Citrus 

🔴Additional information::
-Parthenogenesis: Formation of embryo from unfertilized egg
-Apospory & Apogamy: Formation of embryo from any other cell of embryosac (other than the egg) without fertilization