Principles of Plant Breeding (2+1)

Introduction

• Apomixis, is a type of reproduction in which sexual organs or related structures take part but seeds are formed without union of gametes. It refers to the occurrence of an sexual reproductive process in the place of normal sexual processes involving reduction division and fertilization.
• Winkler (1908) defined apomixis as “the substitution for sexual reproduction or another asexual reproductive process that does not involve nuclear or cellular fusion (i.e. fertilization)”.It was first reported byLeuwenhock as early as 1719 in Citrus seeds.
• Apomixis is widely distributed among higher plants. More than 300 species belonging to 35 families are apomictic. It is most common in Gramineae, Compositae, Rosaceae and Rutaceae. Among the major cereals maize, wheat and pearl millet have apomictic relatives.