Induced Parthenogenesis with an Apomict-Derived Gene

Apomixis in Pennisetum/Cenchrus is the consequence of aposporous embryo sac development and egg cell parthenogenesis, processes controlled by at least two linked genes within the apospory-specific genomic region (ASGR).  Parthenogenesis of unreduced eggs occurs in natural apomicts within the genus and backcross lines of pearl millet in which the ASGR-carrier chromosome has been introgressed.  Parthenogenesis of reduced eggs is rare in natural and synthetic apomicts, but frequent in sexual pearl millet, rice and maize when transformed with an AP2-domain transcription factor-encoding gene from Pennisetum squamulatum (Cenchrus squamulatus).  Haploid plants can be recovered from parthenogenetically-derived embryos.  This gene has potential utility for haploid induction through parthenogenesis in reduced eggs or apomixis through induction of parthenogenesis in unreduced eggs.