Question

When embryo develops from nucellus, it is known as

• A. Recurrent agamospermy
• B. Adventive polyembryony (sporophytic budding)
• C. Non-recurrent agamospermy
• D. None of the above

Answer 1

The correct option is B Adventive polyembryony (sporophytic budding)

Apomixis refers to substitution of the usual sexual reproduction by a form of asexual reproduction which does not involve meiosis and syngamy. There are two main categories of apomixis- Vegetative reproduction (plants propagate through body parts other than seed) and Agamospermy (seed is retained as agent of propagation but the embryo is formed by some process in which normal meiosis and syngamy have been eliminated).
Two different types of agamospermy have been recognized based on whether the embryo develops from a cell of the unreduced female gametophyte (gametophytic agamospermy) or directly from diploid sporophytic cells of the ovule such as nucellus or integuments (sporophytic or adventive embryony). In adventive embryony spore is not differentiated.
When embryo develops directly from a diploid egg the process is also called as recurrent agamospermy. In Non-recurrent Agamospermy, embryo develops parthenogenetically from haploid egg.