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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 1


































































             AꎬCꎬGꎬH. 不同发育时期的花药横切面ꎬ包括小孢子母细胞时期(A)、小孢子减数分裂期(C)、小孢子四分体时期(G) 和 2-细
             胞型四合花粉期(H)ꎬ示意早期每个药室的小孢子囊中央出现一条不完全贯穿的不育隔膜组织ꎬ花药成熟时发生降解形成一个
             深裂花粉团ꎻ BꎬD. 不同发育阶段的花药纵切面ꎬ包括孢原细胞时期(B)和小孢子母细胞时期(D)ꎬ 示意不育隔膜组织发生ꎻ Eꎬ
             F. 小孢子母细胞时期的不育隔膜组织(E)和内绒毡层细胞具 1 ~ 2 层ꎬ为单核(箭头所指)ꎮ c. 合蕊柱ꎻ cn. 药隔组织ꎻ ds. 中萼
             片ꎻ lip. 唇瓣ꎻ ss. 隔膜组织ꎻ po. 花粉团ꎮ
             Aꎬ Cꎬ Gꎬ H. Cross sections of an anther at different developmental stagesꎬ including microspore mother cell (A)ꎬ microsporogenesis (C)ꎬ
             microspore tetrads (G)ꎬ and 2 ̄celled pollen tetrads (H)ꎬ indicating a pair of thecae bending toward a labium and an incomplete sterile septum
             differentiatedꎬ unequally dividing a micropsporangiumꎬ resulting a cleft pollinia due to its degradationꎻ Bꎬ D. Longitudinal sections of an anther
             at primordium (B) and microsporogenesis (D)ꎬ noting differentiation of a septum (B)ꎻ Eꎬ F. Cell morphological features of a sterile septum
             at microsporogenesisꎬ showing 1-2 layers of inner tapetum with uni ̄nucleated cells (arrows indicated). c. Columnꎻ cn. Connective tissueꎻ
             ds. Dorsal sepalꎻ lip. Labellumꎻ ss. Sterile septumꎻ po. Pollinium.
                                       图版 Ⅱ  云南火焰兰一对深裂花粉团的发育过程
                            PlateⅡ  Development of a pair of deeply ̄cleft pollinia in Renanthera imschootiana
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