title: Sexual reproduction development in apomictic Eulaliopsis binata (Poaceae).
abstract: Apomixis is a particular mode of reproduction that allows  progeny formation without meiosis and fertilization. Eulaliopsis binata,  a tetraploid apomictic species, is widely used for making paper, rope and mats.  There is great potential for fixation of heterosis in E. binata due to  autonomous endosperm formation in this species. Although most of its embryo sac  originates from nucellus cells, termed apospory, we observed sexual  reproduction initiation in 86.8 to 96.8% of the ovules, evidenced by callose  deposition on the walls of cells undergoing megasporogenesis. However, only  2-3% mature polygonum-type sexual embryo sacs were confirmed by embryological  investigation. Callose was not detected on aposporous initial cell walls. The  aposporous initial cells differentiated during pre- and post-meiosis of the  megaspore mother cell, while the sexual embryo sac degenerated at the megaspore  stage. DNA content ratio of embryo and endosperm in some individuals was 2C:3C,  based on flow cytometry screening of seed, similar to that of normal sexual  seed. These results confirm that apomictic E. binata has conserved  sexual reproduction to a certain degree, which may contribute to maintaining  genetic diversity. The finding of sexual reproduction in apomictic E. binata could be useful for research on genetic mechanism of apomixis in E.  binata.
authors: College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China.
authors: J J
authors: JJ
authors: Li
authors: L
authors: L
authors: Liu
authors: Y D
authors: YD
authors: Ouyang
authors: J L
authors: JL
authors: Yao
mesh_terms: D060832:Apomixis / Q000502:physiology*; D056625:Endosperm / Q000196:embryology* / Q000235:genetics; D014644:Genetic Variation / Q000502:physiology*; D006109:Poaceae / Q000502:physiology*; D011123:Polyploidy