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1 期 王乐骋等: 云南火焰兰的花形态和花药发育的胚胎学特征 8 3
A. 孢原细胞通过有丝分裂形成小孢子母细胞ꎻ B-F. 小孢子发生过程:减数分裂 I 前期(B)ꎬ 减数分裂Ⅱ前期(C)ꎬ 减数分裂Ⅱ
后期ꎬ 注意 2 个子核之间无子细胞壁产生 (Dꎬ 箭头)ꎬ 小孢子四分体排列方式有正四面体(E)和左右对称(F)排列ꎻ GꎬH. 雄配
子体发育过程ꎬ 小孢子保持在四分体内继续有丝分裂(Gꎬ 箭头)ꎬ 形成小的生殖细胞和大的营养细胞ꎬ 发育形成 2-细胞型花粉
(H)ꎮ gc. 生殖细胞ꎻ vc. 营养细胞ꎮ 比例尺 = 10 μmꎮ
A. Archesporial cells divided into two daughter cells and differentiated as microsporocytesꎻ B-F. Meiosis of microspore mother cells: Prophase I
(B)ꎬ ProphaseⅡ (C). Anaphase Ⅱꎬ noting absence of new cell wall of daughter cell (Dꎬ arrows indicated)ꎬ and microspore tetrads with
tetrahedral (E) and isobilateral (F) arrangementsꎻ Gꎬ H. Microspores retained in tetrads underwent a mitotic division (Gꎬ arrows indicated)
and produced 2 ̄celled pollens (H). gc. Germ cellsꎻ vc. Vegetative cells. Scale bars = 10 μm.
图版 Ⅳ 云南火焰兰的小孢子发生和雄配子体发育
Plate Ⅳ Microsporogenesis and male gametophyte development in Renanthera imschootiana