Principles of Plant Breeding

Apomixis

• Here, sexual organs or related structure form seeds, these are four important forms:

a. Apogamy: Here embryo develops from cells other than egg cells i.e., Synergids or Antipodal cells of embryo sac. E.g. Onion, Lilly. The resultant plants may be diploids or haploids.

b. Apospory: Embryo develops from cells other than embryo sac cells i.e., cells of integuments or nucleus.E.g.Citrus and Mango.

c. Diplospory: Embryo develops directly from megaspore mother cell, which may be diploid or haploid.

d. Parthenogenesis: Seedless fruits are formed from ovary without fertilization Embryo develops from either male or female gamete without fertilization. They are haploids and may be diploids depending on the ploidy level of egg cell.