狭叶柴胡大小孢子发生和雌雄配子体发育的研究

用石蜡切片法、半薄切片法对狭叶柴胡的大、小孢子发生和雌、雄配子体发育进行观察研究。结果显示:(1)狭叶柴胡花药壁的发育为双子叶型,腺质绒毡层;小孢子母细胞减数分裂过程中的胞质分裂为同时型,四分孢子为正四面体形;成熟的花粉粒为3-细胞型,具3个萌发孔。(2)倒生型胚珠,单珠被,薄珠心;大孢子母细胞常为一个雌性孢原直接发育而成,大孢子四分体呈线型,多数情况为合点端一个大孢子分化为功能大孢子;由功能大孢子发育为蓼型成熟胚囊。(3)八核胚囊时期,珠心基部和两侧的一些珠心细胞留存较久,成为珠心座细胞。此外,珠被内表皮细胞发育为珠被绒毡层。     

北柴胡大小孢子发生和雌雄配子体发育的研究

用石蜡切片法对北柴胡的大、小孢子发生和雌、雄配子体发育过程进行观察研究.结果显示,北柴胡的胚珠为倒生型,单珠被,薄珠心.孢原细胞不经分裂直接发育成大孢子母细胞;四分体线性,多数情况下合点端的大孢子为功能大孢子,少数情况下亚合点端的大孢子也可发育为功能大孢子,蓼型胚囊;八核胚囊时期,珠心基部和两侧的一些珠心细胞保持自己的细胞质和形状,留存较久,成为珠心座细胞,珠被内表皮细胞发育为珠被绒毡层;花药壁发育类型为基本型,绒毡层为腺质绒毡层.小孢子母细胞减数分裂的胞质分裂为同时型,产生正四面体型四分体.成熟花粉为3细胞型.     

柴胡大、小孢子发生及雌、雄配子体发育

以柴胡(Bupleurum chinense)为研究对象, 运用石蜡切片技术对其大、小孢子发生及雌、雄配子体发育进行了研究。结果表明: 柴胡花药具4个药室, 花药壁由表皮、药室内壁、中层和绒毡层4层细胞构成, 花药壁发育为双子叶型, 腺质绒毡层。小孢子母细胞减数分裂的胞质分裂为同时型, 产生正四面体型小孢子。成熟花粉三细胞型。胚珠倒生型, 单珠被, 薄珠心。大孢子母细胞常为一个雌性孢原直接发育而成, 大孢子四分体呈线型或T型排列, 多数情况为合点端一个大孢子分化为功能大孢子, 由功能大孢子发育为蓼型成熟胚囊。在胚囊发育过程中, 珠被内表皮细胞特化成珠被绒毡层。同一朵花中, 雄蕊先熟, 记 录了花蕾大小及雌、雄配子体发育的对应关系。     

柴胡大、小孢子发生及雌、雄配子体发育

以柴胡（Bupleurum chinense）为研究对象,运用石蜡切片技术对其大、小孢子发生及雌、雄配子体发育进行了研究。结果表明：柴胡花药具4个药室,花药壁由表皮、药室内壁、中层和绒毡层4层细胞构成,花药壁发育为双子叶型,腺质绒毡层。小孢子母细胞减数分裂的胞质分裂为同时型,产生正四面体型小孢子。成熟花粉三细胞型。胚珠倒生型,单珠被,薄珠心。大孢子母细胞常为一个雌性孢原直接发育而成,大孢子四分体呈线型或T型排列,多数情况为合点端一个大孢子分化为功能大孢子,由功能大孢子发育为蓼型成熟胚囊。在胚囊发育过程中,珠被内表皮细胞特化成珠被绒毡层。同一朵花中,雄蕊先熟,记录了花蕾大小及雌、雄配子体发育的对应关系。     

山茶科核果茶属和石笔木属的胚胎学研究

观察了短叶核果茶,石笔木,粗毛石笔木和屏石笔木的大小孢子和雌雄配子体的发生和发育过程,４个种的胚胎学特征高度相似,均为基本型药壁发育,腺质线毡层,同时型小孢子母细胞胞质分裂,四面体形小孢子四分体,二细胞成熟花粉,倒生胚珠,双珠被,薄珠心,单孢原,蓼胚囊,卵细胞与助细胞区分明显,均具有珠被绒毡层和承珠盘,以蓼型胚囊区别于邻近的山茶属。     

革苞菊胚胎学研究 Ⅰ.大、小孢子发生和雌、雄配子体发育

革苞菊为雌雄异株。在雄花中 ,花药 4室 ,药壁发育为双子叶型 ,由表皮、药室内壁 ,一层中层和绒毡层组成。绒毡层于小孢子四分体时期开始变形 ,其细胞原生质体向药室中移动 ,为变形绒毡层。小孢子孢原为多细胞 ,小孢子母细胞减数分裂产生四面体型的小孢子四分体。四分体胞质分裂为同时型。成熟花粉 3-细胞型。单核期的小孢子出现壁发育不良和巨大及空花粉现象。在雌花中 ,胚珠是倒生的 ,单珠被 ,薄珠心 ,珠被于孢原期已发育完整。大孢子孢原单细胞。由孢原细胞直接发育形成大孢子母细胞。 4个大孢子直线型 ,蓼型胚囊。于成熟胚囊期观察到发育异常的胚囊。通过对胚囊发育过程中营养物质消长规律的研究 ,讨论了环境与发育的相关性问题。     

籽银桂雌雄配子体的发育研究

利用石蜡切片和扫描电子显微镜技术。研究了南京地区银桂品种群的‘籽银桂’雌雄配子体的发育过程。雄蕊的孢原细胞在8月中旬出现。花药壁的发育为基本型,分泌型绒毡层。小孢子母细胞减数分裂为同时型。形成的4个小孢子四分体呈典型的四面体型。成熟花粉粒即雄配子体为二核花粉粒。籽银桂为倒生胚珠。单珠被,薄珠心。珠被内层细胞特化为珠被绒毡层。在胚珠合点端。有承珠盘结构。在9月中旬,雌蕊的孢原细胞开始分化出来。孢原细胞直接发育成大孢子母细胞,然后大孢子母细胞减数分裂形成大孢子。‘籽银桂’的胚囊发育类型为蓼型。成熟胚囊即雌配子体由2个助细胞、1个卵细胞、1个中央细胞(2个核)和3个反足细胞组成。     

濒危植物瑶山苣苔的大小孢子发生和雌雄配子体发育研究

利用石蜡切片技术对瑶山苣苔大小孢子发生、雌雄配子体发育及胚胎发育进行了细胞学观察,结果表明:瑶山苣苔胚珠倒生,单珠被,薄珠心,具珠被绒毡层。大孢子母细胞减数分裂形成的四分体呈直线排列,合点端的大孢子发育为功能大孢子,其余3个大孢子退化,胚囊为单孢子发生的蓼型胚囊发育方式。花药为四囊形,花药壁由外到内依次为表皮、药室内壁、中层和腺质绒毡层,小孢子形成时胞质分裂为修饰性同时型,小孢子四分体排列方式为四面体形,成熟花粉为2核细胞。胚乳发育为细胞型,在胚的发育过程中被吸收耗尽。瑶山苣苔大小孢子发生和雌雄配子体发育基本正常,不是导致其濒危的原因。但瑶山苣苔果实成熟时,胚仅发育至球形胚时期,需要经过一定时间休眠才能完成形态后熟,表明胚未发育完全可能是该物种天然更新困难的原因之一。     

金银忍冬雌雄配子体发育的解剖学研究

对金银忍冬(Lonicera maackii(Rupr.)Maxim)大、小孢子的发生和雌、雄配子体的发育过程进行了研究,结果表明:(1)4月上中旬,幼嫩的花粉囊壁由表皮、纤维层、中层和绒毡层共4层细胞组成,绒毡层类型为变形绒毡层。4月15日左右小孢子母细胞进行减数分裂形成四面体型四分体,四分体时期后,部分小孢子为空瘪状态。4月23-26日即将开花时形成三细胞型的成熟花粉。(2)子房三心皮,中轴胎座,胚珠倒生,单珠被,薄珠心。4月下旬开花前发育形成成熟胚囊,胚囊的发育为蓼型,合点端具有承珠盘。研究结果表明金银忍冬雌雄配子体的发育均属正常。     

凹叶厚朴大、小孢子发生和雌、雄配子体发育的研究

凹叶厚朴花药四囊型,腺质绒毡层有1-2层细胞,小孢子形成时胞质分裂方式为修饰性同时型,小孢子四分体排列方式为左右对称型．成熟花粉粒为二细胞型。四分体和小孢子在发生时有不规则变形。子房单心皮,心皮腹面壁上着生2个胚珠,胚珠倒生型,厚珠心,双珠被;孢原细胞一个,并且自表皮下第2层细胞处分化。胚囊发育为单孢蓼型。凹叶厚朴的胚胎学特征与木兰科其它植物的胚胎学特征基本相同,属于较原始的被子植物胚胎类型。在凹叶厚朴大、小孢子发生和雌、雄配子体发育过程中存在部分败育现象。本文初步探讨了凹叶厚朴濒危的生殖生物学原因。     

笔竹大小孢子发生及雌雄配子体发育研究

为探讨笔竹(Pseudosasa viridula)结实率低的原因,该文通过采用石蜡切片的方法结合显微技术对笔竹大小孢子发生及雌雄配子体的发育过程进行研究.结果表明:(1)笔竹的雄蕊多为3枚,极少有6枚,每枚花药具有4个花粉囊.(2)花药壁发育为基本型,由4层细胞构成,由外向内依次为表皮细胞、药室内壁细胞、中层细胞和绒...     

濒危植物——长喙毛茛泽泻的雌雄配子体发育

长喙毛茛泽泻 Ranalisma rostratum stapf 小孢子母细胞的减数分裂过程为连续型,四分体为左右对称型。成熟花粉为三胞花粉。花药绒毡层为变形绒毡层。雌蕊由多数单室子房构成,每子房中含一具双珠被、薄珠心的倒生胚珠。胚囊发育为葱型。成熟胚囊中三个反足细胞退化;二个极核分别位于中央细胞的两端,其体积相差明显。这种极核分布可能与反足细胞过早退化有关。     

Development of the male and female gametophyte in Capsicum annuum L. var. California Wonder

The study of reproductive organs and their developmental stages during sporogenesis and gametogenesis is an important step for basic and applied sciences. In this order and to develop knowledge about Capsicum annuum L. (Solanaceae), flower buds in different developmental stages were investigated by light and scanning electron microscopy. The bell pepper bisexual flowers have homoantherous stamens with tetrasporangiate anthers. The pattern of anther wall formation is basic type, while previously described as dicotyledonous type. Microspore mother cells meiosis has simultaneous cytokinesis and tetrads are tetrahedral. Two-celled mature pollen grains are tricolporate with scabrate ornamentation. The gynoecium is bicarpellate and epigynous, with hemianatropous, unitegmic and tenuinucellate ovules. After megaspore mother cell meiosis, cytokinesis is simultaneous. The chalazal megaspore of the linear tetrad functions as the functional megaspore. Embryo sac development is of monosporic Polygonum type and consists of seven cells. We give the first reproductive calendar for the species that allows prognostication of gametogenesis on the basis of sporophytic parameters related to reproductive organ development and floral bud form and size. Some of these developmental characteristics should be useful for comparative studies and investigation of phylogenetic relationships within Solanaceae family.     

香果树花及胚胎发育的细胞学研究

香果树为茜草科香果树属单种属植物,是我国特种古老珍稀濒危树种。对香果树大小孢子发生及胚胎发育过程进行了细胞学观察,观察结果表明：香果树子房两室,中轴胎座,胚珠多数,倒生,单珠被,厚珠心。大孢子四分体排列成线性,靠近合点端的大孢子发育成功能大孢子,珠孔端的3个退化,胚囊发育为蓼型,典型的七胞八核胚囊。雄蕊浅黄色,蝶形花粉囊,小孢子四分体成四面体型,成熟的花粉为二胞花粉。胚胎发育过程经历了合子、原胚、球形胚、心形胚、鱼雷胚5个阶段,种子成熟时,胚发育未完全成熟。本文在香果树大小孢子发生发育切片的观察中未发现异常现象,胚胎发育停留在鱼雷胚时期。     

Diplospory and obligate apomixis in Miconia albicans (Miconieae, Melastomataceae) and an embryological comparison with its sexual congener M. chamissois

Apomixis, or asexual reproduction through seeds, has been reported for species of the tribe Miconieae, Melastomataceae, but details of the process have yet to be described. We analyzed and compared sporogenesis and gametogenesis in the apomictic Miconia albicans and the sexual M. chamissois. The results point to some differences between species, which were related to the apomictic process. In M. albicans microsporogenesis, problems during meiosis and degeneration of its products led to total pollen sterility, while M. chamissois presented normal bicellular pollen grains in the mature anther. The absence or abnormality of meiosis in M. albicans megasporogenesis led to the formation of an unreduced embryo sac and also to egg cell parthenogenesis, which gave rise to the apomictic embryo. Embryo and endosperm development were autonomous, resulting in seeds and fruits independent of pollination and fertilization. Thus, in this species, apomixis can be classified as diplosporic and obligate. In contrast, meiosis was as expected in the sexual M. chamissois, and led to the development of a reduced embryo sac. Despite the divergent pathways, many embryological characteristics were similar between the studied species and other Melastomataceae and they seem to be conservative character states for the family.     

Embryological Studies on Narcissus tazetta var. chinensis

Chinese narcissus (Narcissus tazetta var.chinensis Roem) blooms but has no seeds.Embryological studies on the species were conducted to discover the causes of its sterility.Its anther wall is composed of four layers of cells,and its tapetum is of the secretory type.The cytokinesis of microspore mother cells is of the successive type,and the tetrad is tetrahedral.During meiosis of microspore mother cells,some chromosomes lagged,and several micronuclei were found in tetrads.Only 27.7% of the pollen grains contained full cytoplasm,and 1.3% of them germinated in culture medium.No pollen grain,however,could germinate on the stigma.The ovary is trilocular with axile placenta,and the ovules are bitegmic,tenuinucellate,and anatropous.Its embryo sac is of the polygonum type.Most embryo sacs degenerated,and only about 4.5% of the ovules contained a normal embryo sac with an egg cell,two synergids,three antipodal,and a central cell containing two polar nuclei.One reason for the sterility of Chinese narcissus is the abnormality of microsporogenesis and megasporogenesis,in which only a few functional pollen grains and embryo sacs are produced.The other reason is that the pollen grains cannot germinate on the stigma.     

小叶兜兰的果实生长和雌配子体发育

为了解濒危兰科植物小叶兜兰(Paphiopedilum barbigerum Tang et Wang)胚珠和雌配子体的发育过程,采用常规石蜡切片技术对其果实的生长动态进行了研究。结果表明,授粉后60~75 d的蒴果内种子数量迅速增加,到授粉后120 d时种子充满整个蒴果。授粉后40 d的胎座上分化形成多数由1层表皮细胞包被1列细胞的胚珠原基;授粉后60 d时位于胎座指状结构末端处紧靠表皮细胞下方的孢原细胞分化为大孢子母细胞。之后,大孢子母细胞经过减数分裂和有丝分裂最终形成成熟胚囊;授粉后135 d胚囊发育成熟,附着在胎座上的种子个体分化明显。小叶兜兰胚囊的发育类型为双孢子葱型,胚珠为倒生胚珠,薄珠心,单珠被,成熟胚囊为8核。这为小叶兜兰的生殖生物学及繁殖体系的建立提供理论依据。     

西南獐牙菜的胚胎学及其系统学意义

报道了西南獐牙菜的大、小孢子发生及雌,雄配子体发育过程,并以此讨论了獐牙菜属宽丝组和多枝组的分类等级和系统演化关系,西南獐牙菜花药四室;药壁发育为双子叶型;绒毡层二型起源,腺质型;中层细胞2层;药室内壁纤维状加厚,药壁表皮宿存,小孢子母细胞减数分裂为同时型;小孢子四分体的排列为四面体形,成熟花粉为3-细胞型,孔子房为3心皮,1室,胚珠12列,故为超侧膜胎座,薄珠心,单珠被,倒弯生胚珠,大孢子母细胞减数分裂形成4个大孢子呈直线形排列,合点端的大孢子具功能,胚囊发育为蓼型,两极核在受精前融合为次生核,3个反足细胞次生增殖为5-8个,宿存,比较宽丝组和多枝组的胚胎党性一状表明宽丝组从多枝组中分出是合理的,在系统位置上宽丝组较多枝组进化。     

凹叶厚朴大、小孢子发生和雌、雄配子体发育的研究

凹叶厚朴花药四囊型,腺质绒毡层有1-2层细胞,小孢子形成时胞质分裂方式为修饰性同时型．小孢子四分体排列方式为左右对称型,成熟花粉粒为二细胞型。四分体和小孢子在发生时有不规则变形。子房单心皮。心皮腹面壁上着生2个胚珠,胚珠倒生型,厚珠心,双珠被;抱原细胞一个,并且自表皮下第2层细胞处分化。胚囊发育为单孢蓼型。凹叶厚朴的胚胎学特征与木兰科其它植物的胚胎学特征基本相同,属于较原始的被子植物胚胎类型。在凹叶厚朴大、小孢子发生和雌、雄配子体发育过程中存在部分败育现象。本文初步探讨了凹叶厚朴濒危的生殖生物学原因。