Hybrid breeding plays an important role in increasing crop yields by taking advantage of hybrid vigor. Hybrid seed production is difficult in crops, though the three-line hybrid and two-line hybrid breeding method is applied widely in rice. A one-line breeding system involving apomixis instead of sexual crosses would address the challenges imposed during the production of hybrid seeds. It has been difficult to reach sufficient rice seeds with fixed heterosis, possibly because genes activating egg parthenogenesis in other plants do not fully activate rice eggs. The autonomous development of self-activated central cells is also essential for synthetic apomixis, as it maintains the seed-setting rate, but the mechanism is unclear. Therefore, it will be essential to further study the mechanism of apomixis and to examine the use of additional apomixis-related genes for obtaining synthetic apomixis in crops.