Figure 3
Flower landmarks representing male reproductive development. (A) Eight days after initiation, the primary sporogenous layers (arrowheads) have formed. (B) Nine days after floral initiation, the microsporocytes (MS) were visible in the sporogenous tissue as well as the tapetal cells (T). (C) Tapetal cells are binucleated (arrowhead). (D) Microsporocytes 10 days after floral initiation are undergoing meiotic divisions marking landmark 8. (E) Tetrads are enclosed by callose walls (arrowhead). (F) Release of microspores. (G – H) The tapetum is degenerating and the microspores are released 13 days after floral initiation. (I) The microspores become vacuolated 14 days after floral initiation. (J) Bi-cellular microspores. (K) Generative and vegetative cells are visible in microspores. (L) Seventeen days after floral initiation, the microspores show a crescent generative nucleus. (M) Pollen at anthesis. Scale bar, 50 μm (A-I), 20 μm (J-M).