Flower Development Landmarks; Buzgo et al. (2004) | Days after flower initiation in tomato | Perianth organs | Reproductive organs | |
---|---|---|---|---|
 |  |  | Ovary and ovule development | Stamen and pollen development |
(1) Inflorescence formation and flower initiation | 1 | Flattened inflorescence apex becomes dome-shaped. | Â | Â |
(2) Initiation of outermost perianth organs | 2 | Emergence of sepal primordia in a helical pattern. | Â | Â |
(3) Initiation of inner perianth organs. | 4 | Simultaneous emergence of petal primordia in alternating positions to the sepals. Sepals overlay the floral meristem | Â | Â |
(4) Stamen initiation | 5 | Sepals and petals elongate. | Â | Simultaneous initiation of stamen primordia. |
(5) Carpel initiation | 6 | Petals start curling over the stamens | Carpel primordia arise. | Â |
 | 7 |  | Central column that will form the locular cavities arise. | Stamen filament start developing and two anther lobes become visible. |
(6) Microsporangia initiation | 8 | Â | Central column continues to elongate. Carpels fuse at the apex of the ovary. Style initiation. Initiation of placental development. | Primary pariety cells develop into endothecium, middle layers and tapetum. Sporogenous layers visible. |
(7) Ovule initiation | 9 | Â | Ovule primordia begin to emergence from the placenta. | The two lobes of the anther and the locule are distinguishable, microsporocyte and tapetal cells are distinguishable. Binucleate tapetal cells. |
(8) Male meiosis | 10 | Â | Â | Microsporogenesis. Microsporocytes or microspore mother cells undergo meiosis I and II and forming tetrads. |
(9) Female meiosis | 11 | Â | Megasporogenesis. Megaspore mother cell (meiocyte or megasporocyte) is visible. Meiosis I. The nucellus is small resulting in a tenui-nucellate ovule. | Â |
 | 12 | Petals grow to the top of sepals | The single integument begins to grow over the nucellus resulting in unitegmic ovules. | Callose wall surrounding the tetrads degrades releasing the microspores. Tapetum starts degenerating. |
 | 13 | Petals emerge from the sepals. | Micropyle development. | Free microspores are being incased in a thick polysaccharide wall; tapetum degenerated. |
 | 14 | Onset of sepal opening | Megagametogenesis and development of the embryo sac. | Microspores come vacuolated, and begins asymmetric mitosis |
 | 15 |  |  | Bi-cellular pollen grain. |
 | 16 |  | Ovule development nears completion. | The vegetative cell and generative cell are well distinguishable |
(10) Anthesis | 19 | Petal opening | Â | Â |