Fig 1.
Microspore and microgametophyte development of Clematis serratifolia.
(A-B) Flower bud differentiation; (C) Archesporial cell (arrow); (D) The archesporial cells divided into primary parietal cells and primary sporogenous cells (arrows); (E) Division of primary parietal cells (arrows, up and middle) and primary sporogenous cells (arrow, down); (F) A row of secondary sporogenous cell; (G) Microsporocyte cells at prophase of meiosis I (arrow); (H) Microsporocyte cells at metaphase (arrow, up) and anaphase of meiosis I (arrow, down); (I) Microsporocyte cells at telophase of meiosis I (arrow); (J) Microsporocyte cells at metaphase (arrow, down) and anaphase of meiosis II (arrow, up); (K) Microsporocyte cells at anaphase of meiosis II (arrows); (L) Microsporocyte cells at telophase of meiosis II (arrows); (M) Symmetrical microspores tetrads; (N) Disintegration of tetrad; (O) Monokaryotic centered stage microspore; (P) Monokaryotic side stage microspore (arrows); (Q) Microspore at metaphase; (R) Microspore at telophase, vegetative cell and germ cell are formed (arrow); (S) The mature anther structure, and the mature pollen with two-celled.
Fig 2.
Scanning electron microscopy views of pollen grains of Clematis serratifolia.
(A) The pollens of Clematis serratifolia; (B-C) Pollen in the equatorial view and in the polar view; (D) The ornamentation in pollen‘s surface.
Table 1.
Pollen characteristics of Clematis serratifolia.
Fig 3.
Megaspore and megagametophyte development of Clematis serratifolia.
(A) Archesporial cell (arrow); (B) Archesporial cell at metaphase of mitosis; (C) The archesporial cell divided into a parietal cell (arrow, up), and a sporogenous cell (arrow, down), which formed into megaspore mother cell; (D-F) Megaspore mother cells at anaphase and telophase of meiosis I (arrows); (G) A linear tetrad of megaspores; (H) The three endostome megaspores degenerated(arrow, middle and down), and the chalazal one was functional megaspores(arrow, up); (I) The volume of functional megaspores increased; (J) Binucleate embryo sac; (K) Tetranucleate embryo sac; (L) Embryo sac with 8 free nucleis; (M-O) Mature embryo sac of seven-cells with eight nuclei; (P) Anatropous ovule. ac, antipodal cell; cc, central nucleus; ec, egg cell; sy, synergids.
Table 2.
Development relationship between gametophytes and flower bud morphology of Clematis serratifolia.
Table 3.
Early embryological characteristics of seven species in Clematis.