Question

Adventive embryony in Citrus is due to:

• A. Nucellus or maternal sporophytic tissues in ovule
• B. Integuments
• C. Zygotic embryo
• D. Fertilised egg

Answer 1

The correct option is A Nucellus or maternal sporophytic tissues in ovule

The formation of an embryo from cells other than the egg cell without the process of fertilsation is called adventive embryony. It is a form of apomixis called as sporophytic apomixis. Adventive embryos may develop from somatic cells of the nucellus or inner integument.

In citrus, some of the nucellar cells surrounding the embryo sac start dividing and protrude into the embryo sac to develop into embryos. Hence, each ovule contains many embryos. This condition is called polyembryony.