柏科4个属(Fokienia、Cupressus、Chamaeyparis 和Juniperus)植物雌球果的发育

通过扫描电镜和常规石蜡切片技术,观察了柏科4个属(Fokienia、Cupressus、Chamaeyparis 和Juniperus)植物雌球果中胚珠的发育及苞片的结构变化.在所有研究的种类中,可育苞片腋部最先观察到的结构是一扁平的突起,并在其上分化出发育为胚珠的胚珠原基.在雌球果的发育过程中,未观察到独立的珠鳞发育.不同的种中,胚珠怕数量和发育顺序有所不同,但苞片的发育是相似的.传粉前,苞片的结构与叶相似.传粉后,由于剧烈的居间维管束发育.我们还对柏科植物雌球果的形态学特性及其可能的演化趋势进行了讨论.     

柏科4个属(Fokienia、Cupressus、Chamaecyparis和Juniperus)植物雌球果的发育(英文)

通过扫描电镜和常规石蜡切片技术,观察了柏科4个属(Fokienia、Cupressus、Chamaecyparis和Juniperus)植物雌球果中胚珠的发育及苞片的结构变化。在所有研究的种类中,可育苞片腋部最先观察到的结构是一扁平的突起,并在其上分化出发育为胚珠的胚珠原基。在雌球果的发育过程中,未观察到独立的珠鳞发育。不同的种中,胚珠的数量和发育顺序有所不同,但苞片的发育是相似的。传粉前,苞片的结构与叶相似。传粉后,由于剧烈的居间生长,苞片发育为盾形,形成球形的球果。另外,在发育后期,苞片内维管系统变得复杂,并且在近轴面有反向的维管束发育。我们还对柏科植物雌球果的形态学特性及其可能的演化趋势进行了讨论。     

侧柏雌球果及其胚珠的发育

观察了侧柏（Ｐｌａｔｙｃｌａｄｕｓ ｏｒｉｅｎｔａｌｉｓ（Ｌ．）Ｆｒａｎｃｅ）胚珠的发育过程及后期球果苞片的结构变化。在北京,雌球果原基７月分化。通常一个球果有４对苞片,中部两对可育,靠球果顶端一对各产生一枚胚珠,其下一对各两枚。胚珠的发育顺序是向顶的,下部可育苞片腑部的两枚胚珠源于同一原基。胚珠原基分化成珠心和珠被,在发育过程中,珠被逐渐包围珠心,最后形成２烧瓶状的胚珠。１１月至次年１月,球果处     

马尾松雌球果的发生和早期发育研究

采用常规石蜡制片技术对马尾松雌球果的发生和早期发育进行了研究。结果表明：雌球果原基发生时间为10月中旬,不同的树龄和着生部位,其发生时间不同。雌球果原基与营养茎端在外部形态及内部细胞组织学分区结构有明显差异。营养茎端外形扁平,内部顶端分生组织结构有顶端原始细胞区、中央母细胞区、形成层状过渡区、周围分生组织区及肋状分生组织区5个明显的分区;而雌球果原基外形呈圆锥状,内部结构只有套层和髓区。12月初,最初的苞片原基在雌球果原基的鳞片的叶腋处产生,之后其由基部向顶部连续发生。翌年1月初,在苞片原基的叶腋处,珠鳞原基发生,发生方向亦为向顶发育。2月底,苞片体积不再发生变化,珠鳞膨大端的基部的近轴面分化出2个倒生胚珠。从雌球果原基发生到胚珠分化历时4个多月。亚热带的冬季气候对马尾松雌球果的生长发育没有明显的抑制作用。     

草麻黄雌性生殖器官的个体发生和畸形式样研究

用扫描电镜观察并分析了草麻黄（Ephedra sinica Stapf)雌性生殖器官的个体发生及畸形式样。该种雌球花个体发生式样与麻黄属其他具双胚朱球果的类群基本一致。外珠被以一对近轴侧突起物出现以及该突起物与苞片成交互排列的发育式样支持前人关于该构造叶性本质的论述,而内珠被与珠心的发育相关,因此可能是真正的珠被,基于返祖性畸形三胚珠球花的出现及其他形态特征,认为麻黄属胚珠数目减少是该属内物种特化的一个趋势;利用雌球花发育的畸形现象及外珠被的形态学本质提出麻黄属的雌球果为复轴性构造,雌性生殖单位是由类似于科达类的次级生殖枝构造经系统发育变态,融合,简化成现存的生胚珠构造式样,每一可育苞片及其腋内雌性生殖单位共同组成了麻黄属的苞鳞－种鳞复合体。     

油松雌球果的发生和发育研究

运用薄切片技术对油松（Ｐｉｎｕｓ ｌａｂｕｌａｅｆｏｒｍｉｓ 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,共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裨的苞片原基,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姨生变化,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     

香榧有性生殖周期的研究

香榧Torreya grandis 是名贵“干果”和木本油料植物,为裸子植物红豆杉科的重要成员之。有关香榧的胚胎学过去有过报道,但其整个有性生殖过程,至今未有详细研究。作者就多年的观察和探索,基本搞清了香榧的有性生殖过程。香榧的球果原基在头年5月1日前已经开始分化,这时原基呈小丘状隆起,在它外面的第一对苞片几乎与球果原基处在同一水平线上。第二年5月1日前后,胚珠的各种组织已基本分化完全,并在珠心深处有一明显的大孢子母细胞。此刻,小孢子叶球中的花粉正处于2细胞传粉阶段。受精作用发生在8月底至9月初。原胚发育持续的时间很长,并在越冬之后于第三年4月开始向幼胚过渡。到9—11月间,种子完全成熟。     

银杏雌性生殖器官的形态学本质及其系统学意义

关于古老裸子植物银杏Ginkgo biloba L.雌性生殖器官形态学本质的问题争论 很多,因此这一类群的分类位置尚存争议。本文进一步发展了Florin提出的“种鳞复合 体(Seed-scale complex)”概念,提出解释裸子植物生殖器官形态演化的“苞鳞一种鳞复 合体(Bract-scale and seed-scale complex)概念和演化理论,并试图用以解释银杏的生 殖器官形态学本质和裸子植物系统发育的有关问题。由银杏着生胚珠的结构(Ovuliferous structure)生于可育短枝上鳞状叶叶腋的事实,赞同该结构为次级轴性(枝性)性质,提 出该次级轴性结构及连同下部的鳞状叶相当于裸子植物大部分类群所具有的苞鳞—种 鳞复合体(Bract-scale and seed-scale complex),并保留了较多的原始古老性质,可能 代表着苞鳞—种鳞复合体较原始的形态式样。该结构的鳞状叶与可育短枝上正常的营 养叶均为不育苞片的性质,鳞状叶叶腋生出的长柄则是次级轴性结构的次生性伸长,长 柄上部二分叉的着生胚珠结构相当于该次级轴性器官仅存的极度退化的二枚可育叶性器 官,而整个可育短枝相当于一个分化程度很低的复合大孢子叶球。银杏生殖器官中的某 些性状与苏铁十分相似,但由于苞鳞一种鳞复合体的出现,标志着这一类群已远较苏铁特 化,并应与所有具苞鳞—种鳞复合体的类群在同一条演化线上,即苞鳞—种鳞复合体 演化线(Bract-scale and seed-scale complex evolutionary line,BS-line),而不具苞鳞 —种鳞复合体的苏铁类(Cycas)则构成裸子植物中的苏铁演化线(Cycas evolutionary line,C-line)。银杏大孢子叶球的式样,可能代表着裸子植物一种早期的原始大苞子叶 球式样,为古裸子植物不甚分化的可育枝条向高度压缩和变态的可育枝条(苞鳞一种鳞复合体及典型的球果)演化的一种中间过渡式样。     

糖蜜草（Melinis minutiflora Beauv．）幼穗分化发育．及花和果实形态的研究

本文对糖密草（ＭｅｌｉｎｉｓｍｉｎｕｔｉｆｌｏｒａＢｅａｕｖ．）的幼穗分化发育及花和果实的形态作了研究,将幼穗分化发育过程划分为以下九个时期：第一苞原基形成期;第一次枝梗原基形成期;第二、三次枝梗原基形成期;小穗及颖花原基形成期;雌、雄蕊原基形成期;花粉母细胞形成期;花粉母细胞减数分裂期;花粉充实期;花粉成熟期。全过程历时约需４２ｄ．从抽穗到颖果成熟约需５０ｄ。糖蜜草的花序为圆锥花序。每花序有可育花２０００—３０００朵．小穗是由小穗轴、内外颖片、不育花外稃和小花构成。小花包括有内外稃各一片、一鳞被、雄蕊三枚和一枚雌蕊,颖果千粒重为９１ｍｇ。     

极小种群野生植物崖柏的生殖物候、传粉及胚胎发育研究

以濒危植物崖柏(Thuja sutchuenensis Franch.)为对象,对其生殖物候、传粉机制进行观察,并采用石蜡切片法对其胚胎发育过程进行研究。结果显示:崖柏于8月分化出大、小孢子叶球,次年3月传粉,为花粉无气囊、具传粉滴、胚珠直立型传粉机制,球果于10月开裂;显微观察发现,传粉期花粉进入珠孔后,贮藏在珠心上方的贮粉室内,同时珠心组织中分化出孢原细胞,进入雌配子体发育阶段,5月中旬,花粉管开始萌发,6月初完成受精,进入胚胎发育阶段,10月初,胚胎发育成熟。研究表明崖柏从大、小孢子叶球形成至种子成熟的整个发育过程中均存在败育,而胚珠败育及雌配子体游离核时期至幼胚发育期间的败育是其生殖障碍的主要原因。本研究获得了崖柏生殖生物学的基础资料,为其人工繁育和制定保护策略提供了重要依据。     

侧柏雌球果及其胚珠的发育

Seed cone in Platycladus orientalis (L.) France consists of four or five pairs of decussate bracts. Usually, two pairs of the fertile bracts in the middle of the cone subtend six ovules, which initiate in an acropetal manner. Only one ovule presents on each of the upper fertile bract, while two ovules initiate from a common primordium in the axil of lower bracts. In Beijing, most female cones initiated in July. All parts of the cone formed before dormancy, which occurred during November to the next January. After pollination in March, bract morphology changed dramatically; intercalary growth of the bract base formed a conspicuous protuberance, in which inverted vascular system developed. Furthermore, ovules on different pairs of bracts initiated in an acropetal manner and two ovules in each lower fertile bract initiated from a common primordium, which was different from the basipetal initiation of ovules and independently formed single ovule as reported by Takaso in Calltris.     

CONE AND OVULE ONTOGENY IN TAXODIUM AND GLYPTOSTROBUS (TAXODIACEAE – CONIFERALES)

Seed cones in Taxodium distichum and Glyptostrobus pensilis occupy the position of permanent shoots and are initiated in the summer preceding spring pollination. Morphological features are similar in the two genera, reflecting their close taxonomic relationship. Ovule complexes originate as two (rarely more) ovule primordia in the axil of each fertile bract but without any indication of a preceding discrete ovuliferous scale. When the nucellus, integument, and micropyle are well developed, a series of up to ll abaxial lobes forms at the base of each ovule pair. They become fused by basal growth. After pollination the common basal meristem of lobes and bract extends by intercalary growth to form the conspicuous “ovuliferous scale” of the mature cone; the lobes enlarge and exceed the ovules. Despite the topographic similarity in the cones of both genera, there are differences in vasculature such that the vascular traces to the axillary complex originate directly from the axial cylinder in Glyptostrobus but from the bract trace in Taxodium. The complex vasculature of the mature cone develops late and primarily as an expression of intercalary growth.     

Female Cone Development in Fokienia, Cupressus, Chamaecyparis and Juniperus （Cupressaceae）

The ontogeny and vascular systems of female cones of the Fokienia, Oupressus, Ohamaecyparis and Juniperus were investigated in detail using scanning electron microscopy (SEM) and conventional light microscopy. In the species examined, in the axils of the bracts, the first recognizable structure was a broad meristematic swelling, from which ovules developed. No ovuliferous scales developed during the ontogeny of the female cones. The number of ovules and ovule developing sequence displayed considerable variation in different species. However, development of the bracts was similar in all of the investigated species. Following pollination, the foliage-like bracts became peltate bract scales due to intercalary expansion, and global cones formed. In addition, the vascular system in the bract scales became intricate, and inverted vascular bundles emerged in the adaxial of the mature bracts. Based on these observations, a morphological interpretation and possible evolutionary trend of the Cupressaceae female reproductive structures was discussed.     

CONE AND OVULE DEVELOPMENT IN SCIADOPITYS (TAXODIACEAE-CONIFERALES)

Ontogeny of seed cones of Sciadopitys, with special reference to the ovule-supporting structure, is studied in material collected in Japan and Massachusetts. Cones are initiated as lateral or terminal structures in summer and complete the formation of most organs before winter. Bract development is well advanced before ovule-supporting structures are initiated. Continued cone development involves the formation of a narrow ridge of tissue in the axil of each fertile bract. This ridge develops a series of nine (but up to 12) apical lobes in centrifugal order, each of which is the primordium of a future tooth on the ovuliferous scale. Ovules are initiated as outgrowths of the adaxial surface of each lobe so that there is a one-to-one ratio between lobes and ovules. Intercalary extension of the ovuliferous scale itself (distally) and the common base of the bract and ovuliferous scale (proximally) greatly extends the complex. The ovuliferous scale eventually exceeds the subtending bract and its apex becomes recurved. Bracts each have a single trace, but each ovuliferous scale has a pair of traces that proliferate distally to irrigate ovule and scale lobe. Intercalary growth results in recurvature of the ovule trace. The organization of the cone is directly comparable with certain Permian fossils. Sciadopitys also seems unique within the Taxodiaceae in its centrifugal development of the ovule-supporting complex.     

毛舞花姜花器官的发生与发育

通过扫描电镜观察了毛舞花姜(Globba barthei Gagne p.)的花序及花器官的发生与发育。3枚萼片原基首先于花顶连续发生,随后花顶的中心凹陷形成环状原基,环状原基进一步分化形成三枚花瓣—雄蕊共同原基,并在花顶的中心形成花杯。共同原基分化形成花瓣和三枚内轮雄蕊,紧接着外轮雄蕊在花杯的顶点发生。远轴的两枚内轮雄蕊延伸生长并相互融合形成了唇瓣,近轴的一枚形成了可育雄蕊;近轴的两枚外轮雄蕊发育形成了成熟花结构中的侧生退化雄蕊,而远轴的一枚缺失。近轴的两枚外轮雄蕊原基起始的同时,3枚心皮原基也在中心花杯的内侧发生而后与外轮雄蕊相间排列。对毛舞花姜花序的发生和发育的观察发现,在花序轴的头几片初级苞片中产生的是珠芽原基而非蝎尾状小花序原基,其形态特征类似于早期的蝎尾状小花序原基,由此推测珠芽很可能是蝎尾状小花序的变异。     

Inflorescence and Flower Development of Globba barthei ( Zingiberaceae)

Inflorescence of Globba barthei is a thyrse . Primary bracts are initiated in a spiral phyllotactic pattern on the inflorescence apex . Cincinnus primordia are initiated in the axils of primary bracts . These promordia develop secondarybracts and floral primordia . The floral primordium continues to enlarge and produce a ring primordium . Sepals are initiated sequentially from the rounded corner of the primordium . The ring primordium separates three common primordium surrounding a central cavity . The adaxial common primordium is the first to separate . This primordium divides transversely and producespetal and fertile stamen . The remaining two common primordium transversely separate and produce respectively a petal and a petaloid . As the flower developing , the cavity of the floral cup becomes triangular . The angles of this triangle are the sites of outer androecial primordium . The abaxial androecia forms slightly earlier than the two adaxial ones, and then this primordium ceases growth soon . The two posterior primordia continue growth to produce the lateral petaloid staminodes . During this stage , gynoecia initiate from the floral cup and continue to fuse and develop into style and stigma. In addition ,Initiation of the bulbil primordium is observed at base of inflorescence axis during the early floral development . The bulbil primordium initiates in the axil of primary bract . The evolutionary significance of six androecia is discussed .