Capturing Heterosis: Progress Towards Achieving Apomixis in Sorghum

Apomixis leads to clonal offspring by conserving the maternal genotype through the avoidance of meiosis and a subsequent lack of fertilization of the egg. Apomixis has significant potential for fixing hybrid vigor from generation to generation in highly productive crops. Our previous work in maize demonstrated that a functional MiMe (Mitosis instead of Meiosis) system will result in clonal progenies, which is currently being transferred into sorghum. A single gene, PsASGR-BABY BOOM-like (BBML), isolated from the apospory genomic region (ASGR) of apomictic Pennisetum/Cenchrus, has been shown to successfully induce parthenogenesis when introduced as a transgene into pearl millet (Conner et al., 2015). Here we demonstrate the potential of this transgene to induce parthenogenesis and haploid seed formation in sorghum. Parthenogenesis was shown to occur at a high percentage of the egg cells. Viable haploid seeds also were produced. We will discuss our results and their implication for achieving apomixis in sorghum utilizing apomeiosis and parthenogenesis approaches.