Principles of Plant Breeding (2+1)

Genetics of apomixes

• Crosses between amphimicts and apomicts belonging to the same species, segregate for the two types of individuals in advanced generations. This suggests that apomixis is a genetically controlled phenomenon in plants. Stebbins (1958) states that, as a rule, the apomictic condition is recessive to sexuality, although polyploid apomicts show tendency towards dominance.
• However, this recessiveness is not usually due to a monogenic difference. Since there is frequent reversion of apomicts to normal sexuality or sterility or some abnormal genetic behaviour in crosses involving in apomict and an amphimict or involving two apomicts of diverse origins, it appears that a successful apomictic cycle is the result of an interaction of many genes which tend to break on hybridization.
• It is only in the relatively simple types of apomixis, like adventive embryony and vegetative reproduction that simple genetic beheaviour can be expected.