Abstract:
The embryo development,seed formation and fruit anatomical characteristics of Cymbidium goeringii var.longibracteatum were investigated by microscopic and ultrastructure obsevation on the capsules at various developmental stages obtained by artificial self-pollination.The results showed that:megasporocyte and mature embryo sac were observed at 60 d and 80 d after pollination resepectively,and the female gametophyte was of polygonum type.Spherical embryo and suspensor structures formed after 120 d,and the suspensor degenerated and embryo body was at the globular stage after 180 d,and development of the embryo was of the solanad type.The seeds were extremely tiny,consisting of endopleura,episperm and undifferentiated globular embryo,accounting for about 24% of the seed embryo volume,and with little content of nutrients,and an air cavity between the seed coats.The ovary was composed of six carpel valves,three of which were fertile with a ’V’ shaped placenta,and the others were infertile carpel valves without placenta.The average weight of a single seed was(3.92±0.40) μg,and the number of seeds in a capsule was(37.98±3.71)×10~4.