烟草柱头表面有两层覆盖物，其中含有少量细小的钙颗粒。花粉落到柱头上后，储存在花粉外壁中的钙被释放到覆盖层中。当花粉管穿过覆盖层长入柱头细胞之间时，花粉管顶端的细胞壁中出现了大量的细小钙颗拉。开花后22h观察时，在花柱引导组织中形成了钙的梯度分布花柱上部引导组织中的钙较少，而下部连接子房处的花柱引导组织中含有较多的钙颗粒。去雄花开花后1d时，花柱上部引导组织中的钙明显增多3d时，连柱头细胞中也出现了较多的钙颗粒。讨论了烟草花柱引导组织中钙梯度分布和花粉管生长的关系。

Nuclear DNA content of male and female gametes of tobacco was determined using 4', 6-diamindino-2-phenylindole and quantitative microfluorimetry. Pollen grains are released with generative cells containing 2C DNA. Mitotic division occurs in the pollen tube 8-12h after germination. The resulting sperm cells have 1C DNA content during pollen tube elongation in the style. Sperm cells deposited in the degenerated synergid have a DNA content between 1C and 2C, indicating that sperm are in S-phase in the synergid. Concomitant with pollen tube arrival, the egg cell increases in DNA quantity from 1C to between 1C and 2C at 48h after pollination. In the absence of pollination, S-phase in the egg cell is delayed by up to 36h. Newly formed zygotes contain nuclear DNA concentrations of 4C at karyogamy and remain at 4C until zygote division. Tobacco displays cell fusion after the completion of S-phase, apparently during G2. Failure to achieve an optimized system for in vitro fertilization in Nicotiana may reflect the challenges of achieving cell cycle synchrony in gametes isolated from pollen tubes. Receptive gametes are presumably those that pass through the protracted S-phase, reaching G2 receptivity and cell cycle congruity before fusion.

高等植物自交不亲和反应是由基因控制、避免发生自花授粉的一种机制。本文介绍以虞美人为主的高等植物在自交不亲和反应中肌动蛋白骨架的动态变化及Ca2+的时空变化，着重阐述花粉管生长被抑制的最初信号传导。

莴苣柱头呈两裂片状，有接受花粉的接受面和非接受面之分。授粉前后，柱头接受面乳突细胞的细胞壁中贮存丰富的细小钙颗粒，而非接受面的表皮细胞壁中的钙颗粒很少。在花柱组织中钙的分布具有明显特征，在同一水平上，钙主要分布在引导组织的质外体中，如细胞壁和细胞间隙中，而在引导组织外的薄壁组织中钙主要分布在的细胞内液泡和细胞壁中以及维管束导管内。在花柱不同水平上，花柱中的钙呈现出梯度分布，顶端各组织中的钙颗粒较少，基部各组织中的钙颗粒较多。授粉后1h花柱基部组织的钙颗粒增多，钙梯度分布现象增强。花柱引导组织中的钙梯度分布很可能是吸引花粉管向下生长的原因。讨论了莴苣花柱引导组织中钙梯度分布特征和花粉管在其体内生长的关系。

减数分裂前，莴苣花药中的钙颗粒很少。减数分裂后，花药绒毡层细胞中的钙颗粒明显增加。同时在花药药室基质中也出现许多细小的钙颗粒。刚从四分体中释放出的小孢子内钙颗粒很少。伴随着花粉外壁物质在小孢子表面的沉积，钙颗粒开始积累在花粉壁部位。随后，小孢子中开始出现钙颗粒。当小孢子开始形成液泡后，钙颗粒向其中聚集，伴随着小液泡融合成大液泡。体积较大的钙颗粒主要集中在液泡中，而细胞质基质中的钙颗粒很少。随着二胞花粉中的大液泡消失。花粉细胞质中的钙颗粒变得很少。在以后的发育中，只有花粉壁中积累较多的钙颗粒。在莴苣花药发育过程中，钙与绒毡层细胞的退化和小孢子液泡形成以及二胞花粉中大液泡的消失有关。而花粉外壁表面积累丰富的钙与以后花粉的萌发有关。

蓝猪耳（Torenia fournieri）胚囊部分裸露出胚珠，在光学显微镜下能清楚观察到卵细胞和助细胞的形态结构。用解剖和酶解-解剖两种方法都能分离出生活卵细胞。用前种方法机械分离出的卵细胞数量较少（5%），但避免了酶对配子识别研究的干扰。在后种方法中加入0.1%纤维素酶和0.1%果胶酶既能使分离更加容易操作，又对卵细胞没有致命伤害，能在短时间内分离出较多的卵细胞（18%）。用酶解-解剖方法也可分离出授粉14h后的合子细胞。

莴苣胚囊发育为蓼型，减数分裂形成的4个大孢子中只有合点端的一个大孢子可继续发育，其余3个大孢子从珠孔端依次退化。大孢子母细胞中的钙沉淀颗粒很少，减数分裂后的四分体中的钙沉淀颗粒稍有增加。以后，4个大孢子中的钙沉淀颗粒在数量上有明显差异：即将退化的大孢子中钙明显减少，而未退化大孢子细胞质中则保持有较多的细小钙沉淀颗粒。大孢子的退化是一种细胞程序死亡现象，细胞中的钙浓度降低时可能启动了大孢子细胞的程序性死亡过程，而细胞中的钙浓度高时则保持大孢子细胞的继续发育。文章首次揭示了大孢子发生过程中钙的分布特征。

系统地总结了被子植物受精过程中某些重要事态的细胞骨架的动态变化及其生物学意义。

Prior research has indicated that the two sperm cells of Nicotiana tabacum are dimorphic, suggesting that they may participate in preferential fertilization during in vivo fusion with the egg and central cells. To probe the mechanism of potential preferential fertilization in this plant, it will be necessary to use modern sensitive molecular techniques. For this purpose, two individual populations of two sperm cells, constituting the Svn (associated with the vegetative nucleus) and Sua (unassociated with the vegetative nucleus), were isolated in the thousands from tobacco pollen tubes with a micromanipulator as a preliminary step toward research on gametic recognition using molecular techniques. Microelectrophoresis of paired sperm cells from a single pollen tube was conducted at different developmental stages. Sperm cells isolated from 1-, 2-, 3-, and 4-cm stylar lengths migrated to the negative pole, with the Sua displaying significantly greater electrophoretic mobility than the Svn, reflecting a more positively charged cell surface on the Sua. The sperm cells isolated from 1-cm style are very sensitive to electron potential in an electrophoretic field, presumably reflecting that they are still in a young state. Differences in cell surface charge between the Sua and Svn may be related with cell fate during fertilization.

A genic male sterile Chinese cabbage, Brassica campestris L. ssp. chinensis Makino, was examined using cytological and cytochemical methods to characterize the process of pollen abortion in this plant. Thick sections of both fertile and sterile anthers at different developmental stages were stained using Toluidine Blue O, Periodic Acid-Schiff's (PAS) reaction and Sudan Black B to detect cytochemical changes that may occur in the distribution of insoluble polysaccharide and lipid storage bodies. Pollen abortion in sterile anthers occurs at an early stage of microspore development. During early microspore development, reductions in the number of starch grains in the connective tissue of fertile anthers coincide with the accumulation of starch grains in cells of the anther wall. In the late microspore stage, a large vacuole forms in the microspore, and tapetal cells synthesize and accumulate lipid droplets. The cellular organization of tapetal cells in sterile anthers appears similar to that in fertile anthers, except for the absence of lipid droplets in cells of sterile anthers and diffusely labeled tapetal polysaccharides, suggesting defects in nutrient storage.