Heterochrony in reproductive development among P. rufum cytotypes

Apomixis in angiosperms is associated with polyploidy and hybridity. In Paspalum rufum, some sexual diploids show apomixis potential. As apomixis seems to derive from a deregulation of the sexual pathway, Soliman et al. carried out a comparison of the reproductive developments and apospory initials (AIs) emergence between diploid and tetraploid cytotypes.

Cytoembryological observations evidence reproductive developmental heterochrony. Megasporogenesis and early megagametogenesis are delayed in tetraploids with respect to diploids. AIs appear in both cytotypes during megasporogenesis, but emerge after meiosis in diploid and along with megaspore mother cell in tetraploids. Results suggest that heterochronic development favours AIs differentiation and apomixis success at the polyploid level.