南酸枣大小孢子发生及雌雄配子体发育过程研究

目的 观察南酸枣雌雄配子的发育过程，初步探究南酸枣雌雄蕊败育的发生原因。 方法 利用石蜡切片观察法研究南酸枣的大小孢子和雌雄配子体的发育过程。 结果 （1）南酸枣雌雄异株、单性花，雄花无子房，雌花具退化雄蕊；雄花纵长大于3 mm时，花药成熟，子房纵长达3.5 mm时，胚囊成熟；（2）雄花成熟花药壁共分5层，由外向内为1层表皮、1层药室内壁、2层中层、1层绒毡层，发育形式属基本型；（3）小孢子母细胞分裂形式属同时型，四面体型小孢子四分体，2-细胞型花粉，见3个萌发孔胞质囊；（4）双珠被、厚珠心；胚囊发育类型为蓼型，后期倒转；（5）雌花退化雄蕊的花药壁5层，雌花具左右对称型小孢子四分体，小孢子期绒毡层解体，小孢子解体后花药空囊，药室内壁略纤维状加厚，表皮此时退化；（6）南酸枣雄花从现蕾到散粉约25 d时间，雌花从现蕾到胚囊成熟约24 d时间。 结论 南酸枣雌雄配子发育模式与漆树科大多数种一致；雄花无雌蕊，系花芽发育过程中雌蕊原基退化所致；南酸枣未见退化胚珠，雌花退化雄蕊具正常的小孢子母细胞、异常的小孢子四分体和小孢子，且绒毡层不正常解体，花药空囊，无花粉粒。

Megaspogenesis,Microsporogenesis and Development of Female and Male Gametophyte of Choerospondias axillaris

Objective To observe the development process of reproductive organs of Choerospondias axillaris, and preliminary explore the cause of pistil and stamen abortion of C. axillaris. Method The development process of microspores, megaspores, male and female gametophytes of C. axillaris were observed by paraffin sectioning method. Results (1) C. axillaris was dioecious and unisexual, male flowers lack pistils and female flowers had staminodes; When the length of male flower was over 3 mm, the anther was almost mature, and when the length of ovary was over 3.5 mm, the embryo sac was mature. (2) The mature anther wall of male flower was divided into 5 layers, 1 epidermis layer, 1 endothecium layer, 2 middle layers, and 1 tapetum layer. (3) The division form of microspore mother cell belonged to simultaneous cytokinesis, tetrahedral microspore tetrad, 2-cell type pollen with 3 germination pore cytoplasmic cysts. (4) The development type of embryo sac was polygonum type which reversed in the later stage with double integument and thick nucellus. (5) In female flowers, the anther wall had 5 layers. Isobilateral tetrad was observed in ovule primordium stage. Tapetum disintegrated in microspore stage. Epidermis tended to degenerate when the anther was empty in the later stage and the anther chamber wall was slightly fibrous thickened. (6) It needed about 25 days for the male flower to disperse pollen after budding, and about 24 days for the female flower to develop mature embryo sac. Conclusion The development pattern of male and female gametes of C. axillaris is consistent with that of the family Anacardiaceae. No degenerated ovule is found in the female flower of C. axillaris, and male flower has no pistil, which may due to the degeneration of pistil primordium during flower bud development stage. Staminodes have normal microspore mother cells, abnormal microspore tetrads and disintegration of tapetum, and anther sac is empty with no pollen grains.