利用扫描电镜技术、叶片离析法和石蜡切片法研究了假鹰爪属Desmos 4种植物和皂帽花属Dasymaschalon 3种植物叶片的形态结构。结果表明：假鹰爪属植物叶片近轴面表皮具大型球状含晶簇细胞和不含晶簇的表皮细胞两种类型，远轴面表皮细胞均具一较小的晶簇；叶肉组织明显分化为栅栏组织细胞和海绵组织细胞，油细胞分布于第2层的栅栏组织和海绵组织内，单位毫米叶宽油细胞数为4～6个；主脉维管组织被薄壁细胞分隔成束状。皂帽花属植物叶片近轴面表皮细胞形状相同，均具一晶簇，远轴面表皮细胞的晶簇和近轴面表皮细胞的晶簇相似；靠近上、下表皮的叶肉组织均分化为栅栏组织细胞，在两层栅栏组织细胞之间分化为一至几层海绵组织细胞，油细胞分布于海绵组织内，单位毫米叶宽油细胞数为2～3个；主脉维管组织形成连续的环状。由此可见两属叶的结构具有明显的差异，因而支持假鹰爪属和皂帽花属为两个独立属的观点。

运用常规石蜡切片方法，结合显微荧光技术对越南篦齿苏铁Cycas elongata小孢子发生和花粉个体发育进行了研究。结果表明：其小孢子叶球5月中下旬开始萌动，小孢子囊着生在小孢子叶远轴面，且3-5小孢子囊以辐射状排列方式聚生成聚合囊。小孢子囊壁由6-7层细胞组成，包括表皮、中层及绒毡层。绒毡层来源于成熟造孢组织的外围细胞，其退化形式为分泌型。6月中旬，小孢子母细胞进入减数分裂5，至6月下旬形成四分体。母细胞减数分裂后胞质分裂的方式与其他苏铁类植物不同，具有连续型与同时型两种类型。6月中旬，小孢子经过" 次有丝分裂后，形成R 细胞的成熟花粉粒。 7月下旬进入散粉状态。在花粉发育过程中，母细胞内淀粉粒的积累及其壁上胼胝质的沉积均呈现规律性变化。

利用薄切片和组织化学方法对油松茎皮层树脂道发育过程中上皮细胞内村脂滴和淀粉粒的动态变化进行了观察研究。在树脂道原始细胞阶段，树脂滴稀少，淀粒粒2-5个；树脂道形成期间，树脂滴数量逐渐增加，体积增大，淀粉粒也呈递增趋势，两者都均匀分布于细胞质中；树脂道成熟阶段，上皮细胞内树滴明显减少，主要分布于靠近腔道一侧的细胞质中，淀粉粒数量变化不大，而体积明显减小，通常分布于远离腔道一侧的细胞质中。在树脂道发育过程中，鞘细胞中树脂滴和淀粉变化不明显。

Resin ducts are common in the Pinaceae. The comparative anatomy of stems and leaves of 50 species and two varieties from ten genera has been investigated. The structure and distribution of resin ducts differ among genera. Resin ducts occur in foliage leaves of ten genera of Pinaceae. Cortical resin ducts are absent in the stems of Pseudolarix and Larix. Resin ducts only occur in the secondary xylem of stems of Pinus, Picea, Cathaya, Larix, Pseudotsuga and some Keteleeria species. All of the epithelial and sheath cells are alive and thin-walled in the resin ducts of stem cortex and mesophyll. Except for Pinus the epithelial cells of resin ducts in the secondary xylem of stems have thick, lignified walls. Comparative study shows there are obvious differences in the resin ducts of different genera; apparent differences do not exist, however, in the resin ducts of different species of the same genus. According to the structure and distribution of the resin ducts in ten genera of Pinaceae, a synoptical arrangement of the genera is given and generic relationships of the Pinaceae are discussed.

The migration of nucleolus to the nuclear periphery and the onset of homologous chromosome synapsis are characteristics of the leptotene to zygotene transition in meiocytes. Little is known about the genes regulating these processes in eukaryotes. Here we report the characterization of morphological defects in prophase I in microsporocytes in the Arabidopsis skp1-like1 (ask1-1) mutant. In ask1-1, the nucleolus of the microsporocyte failed to move to the nuclear periphery throughout prophase I, and the chromosomes failed to synapse, despite the formation of bivalents in late prophase I. We also found that the transcription of the DMC1 gene and ASY1 gene, which were predominantly transcribed prior to zygotene in microsporocytes, was not affected in ask1-1. These findings, and the fact that ASK1 is a component of the SCF ubiquitin ligase, suggest that ASK1 regulates either the leptotene to zygotene transition or events associated with the developmental transition during male meiosis in Arabidopsis.

Apple rootstocks M26 and EMLA 9'COST' shoots propagated in vitro were used for the histological study of initiation and development of adventitious roots after a brief induction pretreatment. The results show that there are differences in mode and timing of initiation and development of adventitious roots between the two varieties. In M26, adventitious roots were directly initiated from the derivatives of the cambium, some of which were immediately transformed into meristemoids in situ 36 h after pretreatment. subsequently, meristemoids differentiated into root primordia. Development of adventitious roots were completed when they emerged at the surface of stem based 10 days after pretreatment. In EMLA 9, before the meristemoids formd, internal cell files were formed by continuous divisions of cambial cells. The cells were regularly arranged in files external to the cambium. On the fourth day after pretreatment, some cells in the outermost layers of these files became meristematic, started to divide and turned into meristemoids, which differentiated into root primordia. The cells of the files between the root primordium and the cambium were transformed into vascular tissues which ocnnected the vascular systems of the adventitious roots and stems.

利用高压冷冻和冷替代欧洲赤松（Pinus sylvestris Carr.）茎皮层成熟树脂道上皮细胞的超微结构进行研究，提示出一种全新的树脂分泌方式。其分泌过程为：一些含有水解酶的高尔基小泡，转移至质膜周围并释放水解酶，从而将质膜溶解形成分泌通道，树脂由此迅速转移至质膜外，然后，通过高尔基小泡相互融合形成新膜片段的方式来修补破损的质膜。

运用薄切片技术对油松（Pinus tabulaeformis Carr.）雌球果的发生和发育进行了研究。结果表明：8月初，雌 球果原基发生，其外部形态发生明显变化，但内部细胞组织学分区结构与营养茎端结构相似；10月中旬，雌球果原基的鳞片叶腋处产生最初的苞片原基，以后苞片原基由基部向顶端连续发生。此时球果原基的顶端结构发生变 化，顶端分生组织区、中央母细胞区和周围分生组织区衍化为套层，肋状分生组织衍化为髓区；翌年3月中旬，在苞片原基的叶腋处，珠鳞原基发生，其发生方向同样呈向顶发育；4月中旬，苞片体积已达到最终大小，此时，在珠鳞基部的近轴面分化出" 个具单珠被的倒生胚珠。油松雌球果原基在秋冬季依然保持生长，其营养茎端则进入休眠状态。尽管营养茎端和生殖端两类原基在结构上并无本质的区别，但在生长特性方面具有显著的差异。

The ultrastrutures of the root protophleom sieveelement at different developmental stages of Arabidopsis thaliana. L. were investigated using the technique of high pressure freezing and freeze substitution fixing specimen. The results show that in the development of hte sieve elements, the nuclei undergo typical characteristics of the programmed cell death (PGD): the nuclear envelopes form emboli, the chromation condenses and aggregates towards the nuclear envelope, which degrades and fully disappears later. Before the nucleus degradatin, neither the nuclear envelope undulation, nucleus lobe nor marked dilation (or bleb) of perinuclear space could be observed. In the cytoplasm of the mature sieve element, there are starch-like granules separately sheathed with a layer of membrane and usually iwth mitochondria around. These granules seem to provide substrates to mitochondria in their function. Small vacuoles orginate from endoplasmic reticulum (ER), and no bigger vacuole was found.